Yeah, people are definitely trying to oversell how well gaming works on Linux, especially now that the Steam Deck is coming out. I've had games rated Platinum and Gold on protondb be completely unplayable due to graphical issues, or fail to even launch. I've also run into Linux specific issues even for games that have native ports, for example, holding down a single key for a long time randomly causes the OS to stop sending signals for it until you release it and press again. It's gotten me killed quite a few times in fast paced shooters when holding down the movement key stops working.