REAPER is absolutely one of the best pieces of software out there. I've been using it too since maybe 2009, though not so much in the last few years (not moved to an alternative, I'm just not doing so much audio these days).
I love the business model, the development cycle, etc. and even though it's not open source it kinda has a similar community feeling. Every bit as feature-filled and capable as any of the industry standards.
"Since 2022" - not a headline-worthy comparison imo
For me it's Irish traditional music. Aside from having an interesting history, the style often takes a very high level of musicianship to play well. A single monophonic instrument can play a tune and the fast-moving stream of notes can simultaneously spell out melody, counterpoint/call-and-response, and harmony, as well as providing a strong rhythmic pulse (it is music to dance to, after all).
I use Jellyfin for movies and TV shows, but never tried for music because I already had Navidrome set up. It is so good, really one of my all-time favourite pieces of software. It greatly repays a well-tagged collection, relying on embedded metadata only. Not sure how Jellyfin works here, maybe there is some ability to scrape album info from online sources (?), but I believe it's pretty strict about directory structure (one folder per album), which Navidrome doesn't care about.