OBS for streaming is amazing.

Ardour is a pretty amazing DAW that can compete with proprietary ones. There’re also loads of FOSS plugins out there that don’t have to hide behind the commercial ones. My favorites are the Calf Plugins and the Luftikus EQ for mastering. Helm and Yoshimi are great synths. Pure Data is lightweight and can compete with MaxMSP.

Krita has already been mentioned.

But, I think what strikes me most is that there’s a lot of FLOSS software out there that just doesn’t have direct proprietary counterpart. Small command-line tools like FFMPEG or ImageMagick. Linux as an customizable OS. Programming Languages to make music like SuperCollider. I never learned how to use proprietary CAD software but recently got into OpenSCAD to model some things and it’s really fun once you get the hang of it. I don’t do this professionally so there’s no need for me to learn Fusion360.

Some have a bit of a learning curve but are all the more satisfying to use once you get into them. People are just too stuck in their “industry standard” (which really just means “the most common product that has been around the longest”), but if you’re not bound to that, there’s just a huge number of programs out there that allow you to do amazing things. That to me is the beauty of FLOSS.