I don't understand why companies don't build specific teams that are 100% remote, with perhaps an onsite project manager (or something like that). Then the team

I don't understand why companies don't build specific teams that are 100% remote, with perhaps an onsite project manager (or something like that). Then the team could develop its own norms and culture, and while it would be isolated from the rest of the company, it collectively gives the remote workers much more of a voice than if they were each on different teams.