It's used everywhere. Just because Google killed their RSS reader at a time - it didn't die. I use it for pretty much all my news, updates from sites. If a site doesn't provide feed, I won't bother visiting it and checking for updates. And I host it myself with miniflux + postgresql.

Blech, podcasts. The one area that is stuck in the awful past where Atom (which is equivalent or better than RSS in absolutely every way) doesn’t exist. But for everything other than podcasts, please everyone, use Atom rather than RSS.

If you run a blog long enough, even these days, you'll eventually get messages from readers asking you to provide, update, and periodically reconfigure your RSS feed.

All YouTube channels (and perhaps playlists?) have a secret RSS feed associated with them. It's exclusively how I consume YouTube, allowing me to avoid all exposure to the recommendation algorithm.

Tip: RSS never actually died, and there are still quite a bit of people that use it every day, including me.