People who hate the graphics are probably going to hate anything. I don't follow twitter Pokemon Communities because usually they are just overly toxic. I see nothing wrong with the graphics. They look fine to me and they are a huge step up from SwShBDSP.
There will never not be no hate. Because there will always be something the PokeCommunity to complain about. But from what I've seen via videos and reviews, everyone loves the crap out of the games.
A lot of people who are hating graphics are comparing it to New Pokemon Snap, which I just don't think it is fair. In that game, we are on a single track and move the camera around. While it would be amazing to have an actual Main Series Game like Snap Graphics, I just don't think it is viable option, especially if they can't even make Kingdom Hearts 3 a hard copy because it is such a big game.