If using a modern variant of Wayland and if the app supports it: yes. Both, especially the latter are pretty big buts.

On Wayland+gnome/plasma I’ve had great luck with games, Firefox is almost there with some bugginess, and video playing apps that use mpv like plex work great. It’s definitely not perfect and you may dive into configuring per app flags to make them utilize hdr, but the easy stuff generally works

Barely works on windows too, though