Nobody wants to play against cold war which have been developed 30 years in the future, it just ruins the already bad progression experience

Thats the thing.. its not necessary at all, but it might be soon if they keep losing more and more players ;)

The game wants you to face vehicles higher up in the research tree even if it means dying to those vehicles because it gives you a 'taste' of what you can get if you keep grinding "Aw man, if only I keep playing, I could get into that vehicle that keeps kicking my ass".

It's a simple trick to keep you coming back for more.

"If I ready up for battle again, maybe I'll have a good match this time"

And it keeps you wanting to grind further and further up the tech tree

"I can't get uptiered again if I'm top tier!!!!"