All day every day. I'm a linux user both at home and at work. The only closed source software I use is Bitwig, steam, and (most of) the games I play.

When I need software that does X, and I have multiple alternatives, my order of preference for exploring goes like this:

1. Anything that can be installed via apt-get
2. Same as above, but with added repos
3. Something found on github with a release ready for download
4. Same as above, but I build it myself
5. Closed source
6. Paid closed source

(Notice how snap isn't in the list?)

Of course, quality of the software matters, which means the list isn't 100% accurate in all cases. Bitwig is paid closed source, but I prefer that over Ardour, and it's IMHO miles better.