sickday

I can't speak for everyone, but I really enjoyed the "get out of your way" style the app has. I also really liked that you had to slide to upvote/downvote on posts instead of having static buttons you can accidentally press. It also had a decent system for switching between multiple accounts. Finally, it's all open source so one could fork it and customize it if they wanted to.

Part of the purpose of NixOS is providing a means to build a reproducible environment that's easy to configure, migrate, and rollout. You can absolutely handle configuration of many different programs using either flakes or the native modules provided by nix. You can customize your entire system from firewall entries, to users and their shells, to the kernel itself and the kernel modules you'd want it to load, all in a single file or multiple files. If you want to try doing all those things in bash scripts, good luck and please share your experiences but don't expect it to be as easy as the Nix ecosystem.

Probably familiarity. A lot of people joining kbin or Lemmy were using reddit for years prior to their move. Its easier to embrace something that's at least familiar than it is to jump right into something totally different.