I think the biggest issue is M365 Copilot was sold as something that would integrate with business data (teams, files, mail, etc.) and that never worked out quite well.
So you end up with a worse ChatGPT that also doesn't have work context.
When you do have that work context MS copilot performs quite well. But outside of that usecase it's easy to see their model is pretty bad.
When you do have that work context MS copilot performs quite well. But outside of that usecase it's easy to see their model is pretty bad.