I'm also at Google. Every single one of my reports who are intending to return to office have expressed concern and stress over unvaccinated peers in the office. Every single one.
Google has 130,000 employees. I've got ~10 reports and not all of them are coming back to in-person work. If 10% of the company doesn't want to get vaccinated, there is a reasonable chance that none of those people end up on my team.
The point is that the presence of unvaccinated people is going to cause stress and problems for other people who are less productive and happy at home and want to return to the office but feel unsafe doing so knowing that they would be sharing space with unvaccinated people.