You must be confusing .NET (formerly .NET Core) with .NET Framework. Which is forgivable, because MS is terrible at naming things. The former stack is a joy to work with since some QoL changes a few years ago—as long as you don't need both a GUI framework
and Linux support, in which case you're pretty screwed. (Our app is still on .NET Framework for that reason.)
I don't know if you were referring to the total install size of apps or to the licence or maybe just how annoying Mono was, but nowadays you can compile down to one binary, optionally with the runtime included. That makes it simpler for Linux sysadmins than Java or even Python, IMO.