When I first got the game, I was a bit frustrated and confused on where to go, what to do, and why sometimes the things I was trying to do weren't working how I expected (like aiming weapons to account for height). While I never fully got through this phase of frustration, it became easier with time as I just tossed more hours into the game and tried things out. The game has a lot of mechanics that are never really explained to you as a player, you have to learn them through trial and error, external resources like wikis and videos, or from asking people in the game. So you have to put considerably more effort into learning the game mechanics than other games in my opinion, but with the higher barrier to entry you're promised deeper and richer game-play as a result.
After getting through the early hurdles of basic front-line grunt mechanics, the game starts being fun. You'd hear people shouting war cries and saying their final prayers on the front lines, you'd get to participate in make-shift pushes and plans to take territory (often failing, but there's fun in the attempts), and overall it's pretty fun so long as you're on the front lines and surrounded by randoms just trying to live in the moment. This is the point in my experience I wish had lasted longer, as you could have fun without worrying about the bigger picture of the war effort and politics.
Eventually I started feeling the squeeze of resources and lack of cohesion on the front lines, which would lead to losing fights and therefore territory. So, I began learning mid-line and back-line logistics, as well as joining clans who invited me. This involved just taking note of what the front-line says they need, then getting it to them. If it's already made in the back-line but just needs transport, you move it to the front line while watching out for enemy forces trying to thwart your efforts. If it's not yet made, you set out to gather resources and/or make it depending on where the bottleneck is.
This is where clan politics and claims to resources come into play, and where many people (myself included) feel the game just goes to hell. Not to say there aren't terrible people on the front-lines barking orders, team killing and reporting you for not following their demands, but it's less common and you can usually avoid them if you just redeploy to another part of the map. However, mid and back-line logistics is a deeply tangled web of resource management and clan territory with a lot of unwritten rules that will have people fuming if you break them. You constantly have to deal with people cursing you out on their mic, team killing you, or reporting you for supposedly "alt-ing" (using another account to join the other team of the war to gain an advantage for your *actual* team) that you feel like you're walking on eggshells. Every action you want to take you can become paralyzed thinking "this'll somehow piss someone off", so you either take the risk or don't. Even if you aren't outright killed or verbally harassed, not a lot of people like you even being near them or their operations. You'll get the cold shoulder or told you can't use a facility even if you're bringing more materials than you're using.
Sure there's plenty of nice people you'll run into too, people who will give you a kind greeting as you drive by or will answer a question you may have. However, that's likely not what you'll remember and set the tone of your sessions. You'll remember the people who kill you for asking where to find a water source to clean your vehicle, or the people who tell you that you can't build in a spot because they plan to build there later (before killing you just to be sure you got the message), or the person who tries to mass report you for "sitting in a place for 2hrs alt-ing" when you were in there 15-20 minutes actively testing out gear you normally don't see as a new player. Oh, and that person will kill you too after cursing you out in their mic.
It's crazy how toxic and hateful your own "team" can be, and even if it's just 10% of your encounters (in my experience it was definitely more) it really does ruin the mood to play unless you just have really thick skin. I can take being insulted, and there's a mute feature for a reason, but the problem lies in you getting hard stopped by your own team in your efforts to play the game and help out in any way you can. The game is complex and hard enough to get into without people making your life miserable.
This is usually where some people say that, so long as you aren't stealing clan-made supplies that they use for events, you shouldn't be having these issues. I guess they assume that the only reason someone would have consistent trouble with other players is when they're stealing tanks and other equipment that takes a while to grind and plan out. I get that no player should feel entitled to free stuff that other player groups grinded for with intent to be used by their group, but there's a line to be drawn between a person taking the fruits of another's efforts and a person being told they aren't allowed to even put their own effort into grinding for that fruit.
Tanks require resources that players will actually block out or kill other teammates for you daring to touch, like they somehow own the raw material nodes the map produces. You'll spend time scrooping materials from full nodes nobody is operating so you can make buildings, only for people to come in and demolish your work and even kill you because they felt it wasn't an ideal spot for that to be built. You'll be a buzzard scrounging for gear off dead bodies on the front line to haul back to base, and you'll be harassed for "taking too many things and wasting them" even though you're literally doing the opposite. You'll dig trenches because people are asking for it to be done and you spent time learning the basics from a guide, only for a group to come up and say you're doing it wrong on purpose, possibly alt-ing, and of course kill you and destroy your work. It's just on and on and on of people going out of their way to make you feel like crap and blocking you from doing things that would help the team. I had more consistent chill vibes from the literal enemy team's players than my own team. I'd run into the same enemy several times on a front and we'd crack jokes or share tips while actively trying to kill one another, meanwhile in that same session having a teammate yell at me for not volunteering to be in his tank and partly blaming me for it being destroyed (not like I was the one who drove it into enemy lines without a manned team in it).
One day you just have your cursor hovering over the "Play" button after coming home from work, and you tense up knowing you'd likely waste a few hours doing something that just makes you feel bad and pisses people off, and opt to play something else. That's where I've been at for a few months now and I'll likely be uninstalling for that very reason. I know it's not everyone who plays that's like this, but there's enough of it to more than ruin the experience for me. I just wanted to have fun and feel like a small cog in a larger war machine. I don't need to feel like rambo or have access to all the gear without grinding for it, and I didn't even want to piss people off just for existing in the same game as them. I just wanted to scroop some days, fight like a dog on other days, and help build structures and transport goods when the need arises. For the players who get frustrated that the front lines' needs don't seem to be met and they crumble as a result, or people seem to be actively ignoring assembling for pushes, just know that there's a good chance that players avoid those things because they've personally experienced too much crap when trying to do them that they've cut their losses.
Oh and while I did give clans some flak, they aren't intrinsically bad. They just have a lot of influence, so encountering bad ones leaves a bigger impact.