SC does not help getting discovered, although the discovery might have happened also through it. And the discovery is most definitely what is problematic with SC because once discovered, the label comes back at the catalogue with a vengeance :)

Patreon could help, but not every artist on SC is fine with staying indipendent when a big label approaches them, at least in the space I follow (electronic/EDM), simply because the real money is in live shows, and you get bigger shows if you have bigger "shoulders"

I think bandcamp is doing well because it's a different service (store first), for different customers (people that mostly can't care less for popular music), where the music uploaded (almost?) never is in copyright gray areas...