Well, I'm an admin for an LMS and instructional designer by day so I use MacOS and Windows at work. I don't really have a beef with either, in fact I've been a Mac user for 20+ years and its still the go to for my photography. I built up my little Linux laptop specifically as a tool for my writing. I prefer using a text editor and MD for most of my writing and I'm working on a book. I am really happy with Solus and hoping to set up my laptop setup as lean an mean writing machine.
I use it for the standard web browsing/email/netflix/fubotv/music stuff. I am also a mathematics teacher, so I use Atom to write/compile LaTex documents, Gedit for webpages, and GeoGebra for making graphs for course notes. I use the GeoGebra portable, which is not ideal - wish it was in the repo - the flatpak rarely works well, so hoping a snap is in the future. Cheers!
Mainly uni stuff: browser, email, rss (Feedreader - thx for having it in the repo!), R (Rstudio - few problems, but solved it on the forum), and LaTeX. From time to time I am also playing some pc games . Civ 5 & EU IV especially