Because let’s be honest, the reason most of these folks are doing this is because they don’t give a crap about the specific company or anything like that. They just want to build cool shit that other people spec out. As long as the pay is competitive one day they might be building a healthcare mobile app, another day an online car dealership portal.
Honestly, I think that is where it’s headed. I know if I went back to being a dev who did 95% of my shit remote, I would much rather be a 1099 “arms length” contractor then I’d be W2 “real employee”. If you are going for the flexibility that remote brings, you might as well make it fully flexible and just be a contract developer… after all you already decided you didn’t give a shit about company politics or culture… you just want to write code! So just become a contractor!