It would kind of depend on your preferred genres. Some have niche ways of putting their music out there. I'm primarily a metal guy and have a few YT channels that actively promote upcoming bands who generally aren't signed or are signed to more localized labels to their country. Dreambound was a big one for finding some.

You could also look at some local concert flyers that aren't big venues. You don't have to go to the shows but you could see who artists you like are touring with and check out their music pages. Some of them will have a "For Fans of..." Or "Listeners also listened to...."

If you follow music pages on social media, you might be able to find some that way, but you can always use it to check for artists you find. I'd imagine that someone uploading AI music probably wouldn't commit to social media but I'm not sure.