Still use Last.fm. Great service and a nice API to boot if you're wanting to make anything music-y. Integrates nicely into Spotify for playback statistics.
Shame it's pretty much on life-support now and any new features seem to behind a paywall.
The API is nice as an end user and it's super easy to integrate it with lots of things, but working with it as a developer not so much. The latest version is pretty RESTful, but the previous API versions that lots of things still use (since it sounds like Last.fm will allow you to keep using it forever even though it's deprecated) are pretty painful.
However, one pain point with all versions of the API is lack of full HTTPS. I've always been really confused why I'd still see HTTP traffic to the Scrobbling API despite giving it an HTTPS scrobbling URL, and what I found is that you authenticate over HTTPS to get a token, but then the API returns a submission URL that's always plaintext HTTP.
I believe you can still send it over HTTPS by rewriting the URL, and I know that this API was designed before the ubiquity of HTTPS, but it's absurd to keep doing this HTTPS --> HTTP redirect in 2022. Even 3rd party scrobbling services like libre.fm copy this behavior. When API docs give you a primary endpoint of a plantext HTTP URL, that's a huge red flag.
However, I do still love last.fm and still try to obsessively scrobble everything I'm listening to since I've discovered a lot of my favorite bands that way, and it's a great way to get recommendations of live music if you're ever traveling somewhere. I think the paywall has been there for a while, but I'm definitely guilty of not supporting it enough despite how much value I've gotten from it over the years.
Shame it's pretty much on life-support now and any new features seem to behind a paywall.