See now I may be unique in this , but I actually think thats precisely how tanks SHOULD be. It should be just the "antitank" class who is best at taking out tanks. (although obviously any class can use one of the many cannons dotted about, I mean in terms of just what the class has). I actually feel that in BF4 there were too many ways to take a tank out, made them seem less like the beasts of the battlefield and more like the toilet paper of the bathroom
Like I say, I went 44-0 in a tank yesterday as a test and I was absolutely gobsmacked that nobody, not a single person in the 32 players on the other side had the brainpower to use a cannon or antitank rockets against me. Instead they just kept running at me throwing nades and making themselves easy kills, all it would have taken was for a couple of them to respawn with the antitank rockets and I would have been buggered, but nope. No adaptability, no thought, no tactics..just run and nade.
In rush, cannon placements are plausible, but even then its only certain areas you can see a clear path, and the slow reload and being pulled out of the view to watch the reload animation, it makes it hard to miss and take a 2nd shot when things have moved around even slightly.
When ive jumped in cannons and one was in my path, it took 4 hits to take him out (he may have been repairing). About 2min later, another tank appeared, shot at me the instance he had the shot, and killed me - same guy. didnt have a clue where i was, BF told him and made it easy for him. Wont be any different from anywhere else, provided you get the finishing hit.
Conquest its pretty much out of the question at a lot of flags, you get your throat slit just looking out the window of a 2nd floor building for more than 10sec! Too many directions they can come at you, and your dead. If the target isnt being distracted by others, so your hits blend in with others, you're the one in paper armour.
As for AT gun, it'd help if the game gave you the AT weapon to begin with, because grenades and TNT are all useless unless you see them coming and can do 4x grenades without being seen (you only get 3 iirc) and the tank is sitting there allowing the nades to land, or can just nicely plop a few TNT next to it which apparently dont stick like C4.
Mines are fine, you can leave them and maybe score a kill, and if your lucky you place them around one in a built up area. Also, none of this really applies to anything except the light tank, because the rest can easily have crew shooting you without you knowing, so you're not safe doing anything in its sight.
You've got no help attacking with rush, because tanks will sit back, you cant push to take them out without getting tanked or sniped. Defending you can at least lay mines and hope for them pushing up.
But the AT gun, you've got a game that doesnt give you them to begin with, and expects you to level up the class before you can unlock it, when its gun is pretty weak and inaccurate, its AT weapons get you killed, and it refuses to register your class rank until you've left the server, if it even registers it at all. Then you've got a website which initially let you buy anything if you had the money, which is now stopping you do that.
Its just a terrible class, it asks you to grind it out with a terrible load-out, till you can rank it up a couple of times in order to get something that is actually useful and finally gives the class a purpose.
Snipers get a perfectly good and very easy 1-hit kill weapon with no inaccuracy & killer flairs (or eternal blinding flairs!), medics get a half decent rifle & health packs, support have LMG that gets more accurate the longer you hold the trigger, tripmines & ammo crates, and the assault class is told to suck it up and get slaughtered and take what pts you can till you can make it a viable option.
Its horrendous, and its no surprise that on a tank & sniper dominating map, people are easily able to 20/50 - 0 it. After a week or 2, and with a game that works, maybe those tanks will be getting something to deal with - until then, they're dominating and mistakes is usually what gets them killed.
Might be fun going 20-0 in them, feeling like iron-man, but its utterly pointless for anyone that has zero interest in playing armored combat.