>>> Local support system: If the only support system someone has is their work one, then being in a remote environment will likely make them go crazy. You need people who have outside support systems so they have people they can interact with on a daily/weekly basis.
I found this really interesting. We've been a "remote first" company for about 2 years now, after being a non-remote company for the prior 3 years to this. Initially, the feedback on remote was great from employees. However, more recently the feedback from 1 on 1s is that "It's not as fun anymore", "I miss the <buzz about the office> <going out for lunch> <random nights out> with colleagues ", from certain people. I think these people fall into this category of not having a strong social life / support group outside of workmates.