Wow, way to exaggerate. I have a social life outside of work, but I'm working ~40 hours a week. Why should those be lonely, isolated, unsocial hours? They're the prime hours of my life!
I sympathize with all your latter points, but that's no reason to make up another.
What are we talking about, here? Having fun? I'm talking about social affirmation, collaboration, feedback, and community memory. There are a thousand social mechanisms for productivity. "Having fun" doesn't have to enter into it.
But it should! Humor is a valid form of communication, and it's my experience that the brightest people are the funniest—see: Tom. Lehrer. Smart teams wield levity among other tools. There is nothing virtuous about dourness or severity. There is a time and place for gravitas and decorum, but it's not 40 hours a week.
Besides all that, it's good for me! As you said, others may have different needs and, in general, humans are evolved to rely on one another to maintain psychohomeostasis. 40 hours is a long time to take me out of range of my evolved external organs.
This can easily be fixed with one of the many available video platforms out there. You are only lonely and isolated if you dont use the tools available to you (or your employer does not facilitate those, which means you should look for another one)
On the other hand, WFH has allowed me to eat healthy and stay fit. I can workout in the middle of the day, take the dog out for breaks and then come back refreshed to get work done. I don’t like working out early morning or at night. So just having the flexibility to focus on fitness in the middle of the day alone has made a massive difference to my health.
But now my employer has mandated working from office all 5 days in a week. I see about 10 people in my entire floor, I don’t work with any of them, cafeteria is crap so I have to go out to eat, 30 minute commute each way. I’m doing the same work, alone, just in an office now. It’s definitely been a net negative for me.