One major point I noticed everyone was not commenting on was the psychological side as seen through management's eyes.
I've been both sides of the table, so to speak, and can understand the perverse motivations that sometimes come into it. Some people in management actually love being in management because of the hierarchy that comes with having subordinates in one area, and a manager desk that overlooks them. The same desire drives such managers to have all-department meetings which serve little purpose. From their perspective, it reinforces their superior status over the individual contributors. When such managers have remote staff they don't get the same validation. They desire people to come in to get their personal validation with everyone sitting around them. At this point there is some post-rationalisation. The various factual benefits of having people in the office are offered. But they are not the true motivators for this kind of manager.
Obviously not all managers are such ego or status driven as this description. But it is not a caricature at all. I have regularly seen this perspective and attitude amongst managers. It is just easier to spot and understand when you are at C-level and have management or senior staff reporting to you.
I believe this is the true explanation for why there has historically been reluctance to offer a remote-first culture in work environments. Of course, with COVID, public health issues have adjusted the power balance here. When COVID is not such a public health matter in a locality, the return to normal now means return but for 3 days. Why 3? I think it is enough days for management to still feel that they are the boss on enough days of the week. Down to 2 days, managers would not feel boss-like.
Lastly I don't want to malign the true managers and leaders we have. Those that want to achieve great results, and circumstantially need to be a manager, just to realise the journey with team contributors are the best type of manager, in my view.