"Unispace finds that nearly half (42%) of companies that mandated office returns witnessed a higher level of employee attrition than they had anticipated." 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.
There's a belief among folks who already favor RTO that the highest performers will also dislike permanent WFH, it seems to me. And given how notoriously difficult it is to reliably measure developer quality, that may be a belief they can harbor long past when you'd expect evidence to have mounted against it.
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.