A lot of those single tracks you see up on Bandcamp are the musicians trying to raise enough money to finish production on work they play live.
It's much easier to play live than it is to record. Recording is a major financial stumbling block for a lot of new musicians, on top of the time and work that takes place inside the studio. Properly mixing a track requires a fine ear, advanced technical knowledge, usually takes at least as long to complete as it did to write and record the track. This gets expensive as well - there's a reason sound production engineers generally make more than musicians.
This is why signing with a label is such a big deal for most bands - having that money up front to complete an album, as well as the label's connections with recording studios and their engineers, removes the biggest obstacle they have for getting their music out there.
Yeah, I saw a bluegrass band called The Deer Creek Sharp Shooters at a festival last year. They played a full hour+ set but only had 3 songs available online anywhere. They said their album was coming later in 2022, but ultimately didn’t release it until this year. A lot of the songs they played live were on that album.
From ancient personal experience, needing a label or money is kind of a myth and kind of isnt both at the same time.
I mean, if you’re a lone artist a DAW, interface, etc isnt dirt cheap, but can be done on a months wages. If you’re a band, hiring a studio is still (thank fuck) an option - they tend to have all the tools, you just have to make sure you’re all prepared, practised, etc. A u87 ai mic is about £3k here. Or hire a studio with one for £1k for a few hours time.
There used to be a really lovely studio in Portsmouth (in the UK) where the guy would record blues and folk artists with his wife helping. Lots of labels went through there. He had a nice 6 foot grand and some old Fender tweeds.