Happy to see they mentioned their API usage won't change. Last year I was working on a small project (https://listeningfacts.com) around spotify's API but they decided to suddenly restrict access to it.

I was able to make it work with last.fm's API with no issue and they're more generous with the information they provide.

I've had the same experience. Spotify abruptly deprecated their recommendations API endpoint (https://community.spotify.com/t5/Spotify-for-Developers/spot...). I recently switched to last.fm and am able to generate recommendations via their API just fine and without being a pro subscriber.

I also had the delight of finding my streams from 2008 still in my history after not logging in for several years.