Last.fm and scrobling was way more accurate 20 years ago than anything available today.
Even iTunes genius was amazing - I shudder to think how much money I blew on $1 songs, but with subscription music there's now no incentive for them to have good discoverability - they get my money either way.
Came here to say this. Last.fm was amazing, and I think they just used old fashioned statistics without much in the way of ML.
It’s still pretty good. I use it for discovery on my self hosted navidrome setup