I can believe 2 things to be true at the same time:
1) Under 30, high achievers that want to move up the corporate chain quickly feel stymied by the lack of mentorship, community, etc. They can't promote themselves well behind a Zoom screen. These folks express dissatisfaction with their direct managers who don't often see them in person.
2) Over 40, well tenured in career, less ambitious, more family focused professionals absolutely hate the commuting, small talk, intra-office BS. They know that they don't want to be an EVP. They just want to be middle class, get paid decently, have a good Work Life Balance, and good job security. They think that they are more effective at doing the work when not distracted by the things that being in person entail. Plus, they don't want to get out of their comfy pants.
The thing is, most of the #1s turn into #2s in about 15 years of corporate work. Most often when they go through a RIF and see the capriciousness of modern corporate job security. The cynicism builds over the years.
I think you are really dialing this in. And the long term impact on the #1s may not be realized until 10-20 years down the road when they become #2s and are materially less qualified and efficient as the #2s of today.
I too think we've zeroed in on the crux of it.
I'll just add what is now a personal opinion, not something I've read any research about: I think a key phrase is that the older and big "I'm just as productive as home" crowd doesn't see a lot of second order effects.
Hypotheses I have:
the WFH folks have less cross pollination, so solutions and ideas are less innovative/creative. The number of problems I've solved because I ran into someone and we chatted for 5-10 minutes and they had an idea" which I never would have reached out to them otherwise, but which solves a real issue...not zero.
There are a lot of bad actors. I'd be shocked if most people in most jobs are actually more productive from the employers perspective I've WFH, vs what the employee thinks.
Distractions - I think kids/spouses/pets change this equation a lot. Using myself as an example, when I WFH, time that might go to a side project or to make something distinctive instead of merely good often gets sacrificed to instead make a nice lunch and eat it, or to give a kid a meal I wouldn't otherwise, or to chat with my wife for a bit when I wouldn't be calling her at 1pm from the office. MAYBE commute time going away combats this...but I am highly suspicious that the commute time becomes work time. It's just more personal time.
PS
@Desert_Power my age does round to 30! It's not just a choice HAHA
I could keep going but my Costco pizza is ready now so...got to go! xD