There's a thing I see all the time online where people massively underestimate human variance. While people have many things in common, they are all over the place when it comes to many important emotional and mental characteristics. There is no one-size-fits all for anything behavioral, not even close.

If they say it's bad for their long term well-being, they very likely know exactly what they're talking about even if your own experience is very different from that.

I initially read the comment the same way, but I believe they were saying that when the pandemic is over you won't be isolated, not that isolation wouldn't be bad for wellbeing.

I'm like the parent commenter in feeling office work helps me:

For me, I don't do social very well, but I still need to interact with people, I get on well with people (AFAICT) but seldom does anyone ever really want to spend leisure time with me. Work forces me to have social interactions that help my "sanity" (by which I mean: a vague hand-wavey notion of mental health).

I'm "happy" day-to-day with hiding away at home; but I tend to spiral downwards as I don't get much social interaction outside of work. Banter is good medicine.

For me this is a midlife thing.

YMMV, and the parent is probably quite different, but that's my recent experience.