Some would consider the fact that Microsoft "competes with Google and Apple in the Cloud" and "has a not so competitive ad platform" and "has a semi competitive voice assistant" and so on is evidence they don't have a monopoly, rather than evidence they do.
they don't have a monopoloy but they are not far away from having more power then when they had a quasi monopoly
the mono in monopoly is in the end irrelevant, what matters is the power and ways you can abuse it. In the past you mainly got that with being a monopoly or duopoly but by now you can archive it by being "just" competitive with the best in a sector, and doing so in docent of areas and slowly integrating all of that into each other
