I'm pretty new2pubnixes, only recently discovered & heard of them. (from small boards, indieweb, thanks Afternoon!) But I'm not new to Linux. I can't think of other use of pubnix other than small indie micro vps hosting. For static pages there are plenty of hosters like neocities. For exploring terminal shell, there are free js based emulators that run in browser, usually with a compiler on a backend, letting you code. So the only use (of pubnix) that comes to mind - is to roll your own custom daemon scripts that should be online 24/7, dynamicly served web apps.
yeah, don't treat a pubnix as your personal free vps..