But if I want to be social why does it have to be people I didnt choose (i.e. co workers). Why can I WFH and socialise with my family/friends who I choose to be with. This is basically nothing to do with remote work and more about isolation.
I think the problem is that "being social with" some group isn't always as easy as it seems. Work and family are sort of two "default" groups that you automatically have access to (even if those groups may not always be fitting or rewarding).
For other social groups, you have to invest effort yourself, and that effort can be a lot: Finding communities in the first place, making contact, staying engaged, being socially fluent enough that others want to keep contact, etc etc.
That's a lot of work and also requires some skill (and even luck sometimes). Not everyone may be willing or able to put in that work.
(Specifically for work environments, I wonder if the "shared misery" aspect might also play a role: In a work environment, everyone knows that you're not here for fun - paradoxically, that might make some social interactions easier, because you can stop interacting without sending a negative message. In contrast, in voluntary activities, this is harder, because the basic expectation is that you want to be there. So talking about interactions that didn't work well socially might be harder.)