It's not that the game is addicting, it's just that there are no decent alternatives.
War Thunder is basically the intellectual version of the FPS games that all the stupid children and mongoloid brains play. Instead of just being based purely on twitch "skills" which require as much intellectual ability as closing popup spam windows, in War Thunder you have to use at least some tactics and strategy. FPS games are like playing Pong on high speed. War Thunder is like playing chess.
The art of gaming is simply dead for big brains. 20 years ago there were tons of games that required brainpower because PC gaming back then was by nerds and for nerds, but then the corporate suits took over and were like "broaden the appeal to we can make more sales" so everything got dumbed down to the lowest common denominator.
My GF asked me if I was "having fun" playing War Thunder, and I looked at her like she was a fucking retard to even consider that sentence a valid question. I don't have FUN playing War Thunder. This game routinely pisses me off and makes me rage. However, when I stomp the entire enemy team and crush them so utterly I can hear the lamentations of their mothers, I feel satisfaction.
I spent weeks grinding for Operation Winter. The vikings had a word for this. They called it Valhalla. Endless war. Endless combat. Knowing only victory and death. Bathing in the blood of your enemies. You get 15 kills and bask in glory and rewards, and think: what should I do now? Should I get in my Honda Fit and tour the local strip mall for my Triumph? Should I microwave some tendies and throw myself a great Feast? But there is only one option. There is only ever one option. To Battle!
Various cultures have alternatively described the gameplay loop of War Thunder as their vision of Heaven or Hell. It is both.