My guess is that you're also more likely to lose your best performers - since they will have higher confidence in being able to find a remote-friendly job somewhere else.
It's not really a WFH/RTO thing so much as a benefits thing. The same would be true for another variable like free lunches.
What we do know is anecdotal evidence of very influential and high performers at various FAANG type companies that have ended up leaving due to forced RTO.
Anecdotally, I work at a large company that fully supports 0% to 100% remote work, and I work with a wide mix. Some people, and some roles, just do better in the office. Others don’t. I’d be very suspicious of forming beliefs based on anecdotes, especially if they coincidentally align to your expectations.
Less certain about roles that are generally technical. The strongest claim for in-office work, collaboration, is mostly a well solved problem for at least software, possible simple administration that just relies on some collaborative spreadsheets. Sitting everyone in a stuffy boardroom all staring at the same boring spreadsheet is likely to cause stress and mental fatigue, not increased collaboration. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7889069/ This is a well known effect.
Even large "interactive" meetings in remote settings can be counter productive - of course not all meetings are bad and one key to being an excellent manager is picking the right people for the right meetings, but the idea that your "top performers" objectively speaking will be the ones experiencing the most stress is seriously suspect.
What is more likely is some combination of workers who either "do well" in high stress environments, usually implying they are healthy and have some effective stress management techniques and as such are recognized as top performers compared to those unable to effectively manage their stress, or those in mainly technical areas have not yet experienced (somehow) the benefits of less stressful remote-work environments. E.g. parents or partners in cramped personal quarters being more distracted compared to e.g. a private office space.
Finally, for those workers that have an active job component where they must e.g. be on site for customer testing or perhaps they are a technical liason, some hybrid approach may work better - in office for resources which are cost prohibitive to simulate or when their role requires them to interact in an another capacity e.g. as a technician, security guard, or triage such as a front desk.
There is also the case where "top performers" are leeching off their colleagues e.g. where they can "get more done" because they can interrogate and corral others but where others are mostly experiencing productivity hits as a result of the constant interruption.
Forcing in office work for everyone means all the people who work better remotely now…simply don’t.
https://news.ycombinator.com/item?id=36501068
We’ll just find out in a couple years or decades by observing who is still standing.
I think the RTO folks are in the latter group. If their work was measured objectively by results, they wouldn't be considered high performers.
Firstly the people who are mandating RTO want to think of themselves as high performers. They want RTO so "high performers want RTO" is obvious to them.
Secondly a lot of non-doing managers want to be able to justify their existance. To do that they need people in the office to distract by walking around and having conversations etc. They can't do this when people are just WFH doing deep work.
Thirdly, if they know a manager wants RTO, then people who want to suck up to that manager will say they want RTO and will come in to the office to actively suck up to the manager. The manager will see these sycophants as high performers because they are spending their time fluffing the ego of the aformentioned manager.
Behavior you describe would never get my any promotion anywhere I worked. Maybe I was just lucky, who knows.