I think musicians have, through much of history, had "portfolio" careers: a bit of teaching, a bit of composing, maybe a dayjob some of the time, and a fair amount of performing. In the 20th century there was a situation where you could reach a huge audience -- but only if you could access the equipment to record your work. And yes, some labels do take unfair advantage of musicians, while others are more equitable. But this thing where recording and distributing your own work required the services of a label meant that some people quite literally became rock stars, and some of them got very, very rich; and the average listener, through radio and television, got a lot more exposure to these musicians much more easily than they would have in e.g. the second half of the 19th century (back then, reaching an audience beyond what you could do by gigging was all about publishing piano sheet music.) So there's this expectation that if you're a good enough musician you, too, can be a rock star; but the reality is, as you say, somewhat different.

That said: what happened toward the end of the 20th century is that duplication and distribution of recordings got really, really easy, and to an extent less centralised. If you're a musician whose work fits a small niche, no, you're probably not going to get a huge following online; but you might well get a better following than you would have if you tried to go through a big label. Everything is a lot less centralised than it was a few decades ago.

I think this does make it a bit harder to reaching "rock star" levels of income, though of course some people do have their work go viral. But it also makes it easier to earn a modest income from music that's a little off the beaten path; there are people out there who are willing to pay for the music they like, and they will go looking for it. My own work is pretty niche: I compose choral music, mostly sacred at the moment, and no traditional publisher of choral sacred music will touch my work because of my commitment to Creative Commons licensing. So I self publish, and release my scores online, and the amount I made last year through Patreon is roughly equivalent to a year at the organist-and-director-of-music gig I left in 2016, while having a lot more flexibility. (That gig was somewhat underpaid, but I'm also somewhat desultory about my online networking, mostly because at the moment I'm working on a PhD). Meanwhile, most sheet music publishers would still want me to be active on social media and sending out links to my work and doing lots of networking.

And that's the thing, I guess: if you sign a deal with a label you still have to do gigs, if you publish your sheet music with a trad publisher you still have to do your own promotion, if you get a contract teaching violin or guitar or trumpet or whatever in a school or a music shop you probably still have to scrounge around for students.

I don't know enough about cryptocurrencies to have strong opinions on whether Steemit, in particular, will have a similar impact on my work; but I don't think @heymattsokol was trying to imply that just putting your content here and not doing any networking would be a viable strategy.