Microsoft Office has gotten way better over the years. They used to design the UX around the idea of "Office Users", not "Mac Users"

This is very frustrating when supporting a mixed team of Mac and PC users on office. I would prefer it to be the same everywhere.

And that's the problem. I imagine those Mac users chose it because they like the OS' conventions. Photoshop seems to have gone the other way from using OS conventions to doing their own thing the same on each platform. iTunes, which didn't always follow macOS conventions, did port everything to Windows.