Was also disappointed by Steemit. I liked the concept and wanted it to work, but in practice the service was 99% people (or bots) trying to game the system uploading garbage. Any real quality content gets drowned among spam.

Systems that promise to pay for content production create a massive, direct incentive to game the system and spam it.

Yep. Don't get me wrong, I really want these guys to win, but the current system is just not good enough. I don't know how exactly they'll go around solving that problem though.

There are well-established systems to pay for content. The problem is that they're very manual, take a big cut, and are relatively selective. They go by names like publishers, labels, studios, and so forth. They actually work for some definitions of work but you have to be OK with relatively high barriers to entry and with a clearly-defined gatekeeper role.

Sounds like youtube.