A general contractor can penalize/blacklist sub contractors who don't take their jobs, too. Of course, most of the time, there are reasonable humans on both sides and this can be solved, whereas the gig services operate at a scale where it feels harder to get mutual satisfaction, which might be one of the core issues.

I'm honestly not sure where this all ends up. The services certainly _feel_ exploitive when you hear about all the horror stories, but turning everyone into employees may then be fraught with new issues of employer<>employee rights and obligations (for ex defined hours, time off, etc)