They should, but they won't. I fully expect that by the time we see "windows 12" that possibility will be fully eliminated.
Ironically they may have to in order to stay relevant. I'd be surprised if you could find a teenager today that if you asked "would you pay extra for an iphone or android phone that you could use without an apple/google account would you?" that their answer wouldn't be "why would I want that? I'd be cut off from the whole ecosystem!"
Copilot's AI is far inferior to the agents in Claude Cowork or OpenClaw. And I think it still uses the OpenAI GPT 4o . Microsoft also put AI everywhere, and with very poor quality.