Not many places are fully remote, and I think most places with a hybrid arrangement generally don't restrict people to a maximum number of days. We have to do at least 3 days, but a lot of our new grads come in 5, along with maybe a quarter of the other staff. Maybe not 5 days every single week, but definitely 9 weeks out of 10. So people who find wfh difficult often (not always I know) have the option to go in more.
And I don't think you can ignore that for some people, the office is a cause of immense stress. And wfh allows them to continue working much more easily.
I have a bad anxiety disorder that has, in the past, led to severe agoraphobia. Wfh full time isn't great for me, because not regularly having to leave the house allows the agoraphobia to creep back in. But equally, 5 days in the office causes me stress as well, and in the past I've ended up signed off work for significant periods.
I also don't think wfh full time is isolating for everyone who does it, depending on the rest of their lives.
Basically I don't think there's any one size blanket statement you can make, either around wfh being detrimental to individuals, or that being in the office is detrimental.
And that's without even mentioning how people with physical disabilities may find more jobs open to them if they can wfh. My DH is visually impaired (not seriously, but cannot drive) so prior to wfh was limited in jobs because of travel - any job needed to be accessible by public transport. His current job involves him going into the office once a month, and we can afford a taxi for that, or I can drive him if I'm wfh. That wouldn't be the case if it was every day.