The consistent response I have gotten from managers is that more or less - people fake work sitting in their homes or work multiple jobs, and we collaborate better when we are sitting in an office. They use this as a force function to pull employees back into the office.
I call BS on all of these. Employees faking work - your hiring problem. Employees working multiple jobs - again your problem, keep them occupied with meaningful work, if not bring in legality to protect your IP or whatever. AFAIK no one working multiple jobs are revealing IPs.
In person collaboration - There may be some truth to this. High profile decisions are best taken in person, that being said during covid almost all decisions were done on Zoom not just for a week or so but for 2 years. Isn't that proof enough that even government level decisions can be done on Zoom ?
Design discussions are best done on Miro/Google docs than on the whiteboard. Multiple people can collaborate efficiently on Miro, especially with an iPad. Not only this, every voice is heard instead of just 2-3 folks standing at a whiteboard and driving discussions.
So many tools that make even pair programming or production debugging a breeze.
I can pretty much negate every argument that mandates in person office presence.
What I really vouch for is in person collaboration events once or twice a month where everyone comes together for a couple of days and hash out key issues and have a totally unstructured time for collaboration.
And of course, have an office for those who want to come in to collaborate. Not everyone has a spacious home, people like to hang out with co-workers during lunch etc. However make it mandatory that all group meetings will be done on zoom, in order to provide equal participation opportunity to remote workers. These hybrid meetings with a few people in a room and a few on zoom are a total disaster.