In previous years I've found new stuff using Pandora Radio, Youtube Music, and occasionally just by browsing music communities. Reddit's listentothis sub used to be really good for finding relatively unknown bands a number of years ago.

Pandora Radio advertises that instead of doing a basic genre or artist comparison, each track they have is manually analyzed for specific aspects of the track like "call and response", "wall of sound", "excessive vamping", so it makes connections crossing genre lines.

Listen to independent radio stations. Usually can find a stream link online and plug into a music player app.

I've never found similar artists to be helpful. Most of the time it's just a worse version of the thing I like. I don't really like stuff that sounds very samey though.

I'm an old man. "Back in my day", we heard by word of mouth, the radio, browsing at music shops, etc.

We can still do that in the digital age. When someone posts a random song, anywhere, check it out. Try checking out internet radio of genres you like (I'm finding a lot of Classical this way currently). Check out Bandcamp and IRL music store every once in a while just see what calls to you. Sometimes, let the cool album art guide you ;)

Depending on how diverse your taste is, you could always try to branch out to something outside of "similar artists". Just look up genre names and start checking them out. If you find something you like, you can use the same " similar artists" approach on an entirely new search space.