Games and audio production. I'm the only one in my linux sysadmin group that still keeps a Windows SSD for booting games and for media creation, I'm also the only one who doesn't suddenly have games break because an update had conflicting library dependencies or something, or a mod broke the game. I also don't have to spend hours combing through debug logs to find out why the game and mods that worked for years suddenly crashes on launch. So instead I can sit there and game while they fix their linux games. We only really have a lan party once a year so Windows SSD + Steam and old game installers makes it thoughtless. Someone running linux for their games inevitably has had to sit out the lan party, or spends the whole time trying to get whatever game working, that for some reason only isn't working for them and works for everyone else.
Basically linux is quite good for gaming, enough that linux bros can feel assured in superiority, however in practice every time I've done a LAN with 10-20 linux sysadmins and we all try to use linux, it's never gone smoothly for everyone. I actually maintain my previous laptops as Windows machines for this case, just so we can help a linux gamer get in on the games when their games break.
The main challenge with linux compatibility, is the variety and inconsistency of linux systems, it's strength can be it's weakness. It used to be Windows GPU drivers that were the bane of gamers back in the 00s-early10s, now it's trying to coax a meaningful error log out of a game that just crashes for no apparent reason on linux out of the blue.