I'd say that's one of the best ways to spend time. It's okay to have a hobby even if it's just rougelike games. Much better than doomscrolling on Tiktok in every way.
Not when it takes precedence over... doing your math homework, touching grass, communicating with a real flesh and blood friend (or parent/sibling), showering...
Discords for xyz are as much universal hangout spaces as they are about xyz