What you want is a feature that all Firefox based browser have. I am not sure about chromium based but ik that brave also have it.

For Nvidia GPU, if u want squeeze the most out of it during gaming. I think there is 2 best options Bazzite(it is immutable so it will be really hard to break) or Nobara. Both of them is fedora base, so unfortunately your familiar with Debian based will not do much.