In my view, the time for buffing and nerfing was during the beta. Once the game is out and I've paid for a game, they shouldn't be radically changing the gameplay.
Changing the power level of different classes fundamentally changes the game. Maybe I want a game where I can be an OP druid or whatever) and smash everything. I do my research and find and POE2 provides that. I buy the game and then Druids are nerfed. The developers have, after the fact, taken away the reason that I bought the game.
As another (ridiculous) example, if I buy a computer chess game, and afterward the developer nerfs the queen so that the queen can move, at most, 4 spaces, I'm reasonably upset whether or not the queen was OP to begin with.
These balance changes may make some people happy, but personally, I wish I had done more research into Obsidians tendency to change gameplay post-release.