Both games have issues that can hurt their player counts/customers, and neither are doing anything substantial to keep them from leaving
VALVe claims to have stuff for TF2 once the aimbot problem is solved, then proceed to do almost nothing about the aimbots.
World of Tanks has a number of issues/frustrating mechanics that put players in a cycle of leaving the game, and coming back to see if things have gotten any better, only to be soon disappointed and leave again. This cycle will continue until the player will eventually quit the game entirely.
WG exist to make money, there's something in their game causing their customers to decline, and thus their money, and they just ignore everything.
I complain about this game quite a bit on discord, but it's only because, just like the several players on the cycle of pain that I mentioned, I genuinely want to see this game improve. I want to see the cycle broken. I want this game to be fun.
Source: https://www.reddit.com/r/WorldofTanks/comments/rwczyr/this_game_reminds_me_of_team_fortress_2/