As a senior developer, if working just in the office as was expected in the past I was distracted by things like a story about the weekend two colleagues are having in the background that sounds amusing, or the junior developer constantly spinning around on his chair to ask a question about something because "you're there". I always had time for that kind of thing but my productivity suffered and I was always frustrated by not getting enough done.
Working from home wasn't all roses either even though I got more work done. I was already doing a balance of WFH as a contractor before covid and that was working well for me, but when covid restrictions happened and I was WFH months on end, I really started to feel the lack of human contact and socialisation. That story about the weekend was something I suddenly craved to hear. My mental state would suffer because I had no life other than sleep, screen, sleep, screen, and then my productivity would start to decline as a result of declining perspective. I think I need some social contact just to stay calibrated.
Now I have a balance, a couple of days in the office, a couple of days at home, it works out well for me. I use the days in the office to catch up with the team, do any serious whiteboarding we need to do, and help out the juniors on the team with any questions they might have. I use my days at home to just crush out code with whatever music I want on in the background.
As you say I think it will shake out. I know some say that people have forgotten the value of hard work and there is a push to get people back in the office full time, but I think having people in the environment that suits their productivity the best is the way forward (edit - and to circle back to the point - taking care of mental states is important to maintaining productivity).