I think one way to do it is start with a genre that has a niche following and internet discussion forums.

For example : Prog is one such community. (Fourm : r/progmetal)

I have routinely discovered bands with <1000 listens on their top song on Spotify on that sub. I have seen these same bands grow to the point of gaining interest from a label. Interest that was fueled by forum members.

Since the genre rewards musical proficiency, even causal listeners (non fans) can have quality discussions with forum members and boost engagement.

IDK, if this works for other other genres too. But, IMO this is one of the better ways to survive in the new musical era.