It's good for senior developers and the self motivated. Difficult for junior roles which need hand-holding. Difficult for parents or those in condos without a seperate space.
The surprising thing for me working at a fully remote company for the first time (Seeq Corporation - over 100 employees) is that, with the right tools, I think it's actually better for junior roles that need more help. For one thing, there's a lot less friction hopping on a video call than finding someone at their desk. Another thing is that results are the only metric you have to go on, so you don't fall into the mistake of assuming someone is doing okay just because they're sitting in front of their computer and not asking for help.
You really need to have a separate room in my opinion. As a remote worker you save a lot of money not travelling and spending money on lunches, and/or can live where space and housing is much cheaper, so this is possible. I built a home office: https://rwmj.wordpress.com/2013/07/10/garden-office-most-mos...
No I hired a couple of people to assemble it (for about $1200). It certainly would have been possible to build it all on my own - it's just a big, complicated shed kit after all - but it probably would have taken me a month so it made far more sense to hire them. I did give it three coats of paint and stain inside and out though!
We have quite a few parents on our fully remote team and generally remote seems to work well for them as it gives them the flexibility to deal with childcare and allows them to spend more time with their kids. It's not uncommon for babies and sometimes older kids to be passive attendees in our Zoom calls.