Yeah, that’s ironically what Microsoft has been moving towards. Collaborative editing is incredible when used properly. But that also means anyone with edit access can mess up your carefully crafted document. Luckily, things like Comments are becoming more commonplace, so people can suggest edits without actually being able to commit them.
It doesn’t solve the copy/pasting issue, but you can copy/paste from PDFs these days anyways. Realistically, even saving it as an image won’t solve that, since most devices can recognize text in images now.