Though I get what you’re driving at, there have been companies that will press your basement demo onto a vinyl LP almost as long as vinyl records have been made (and later cassettes and CDs, of course). They’d do the artwork, too, from “we’ll have an in-house artist do it for lots of money” to “we’ll put your camera-ready art on it for a little extra”. But pre-internet, that meant selling the hard copies at shows and maybe the local indie record store. What one is missing, of course, is the promotion from a label. But the production of hard copies of music hasn’t been a barrier for a long time.