Microsoft is a very open platform regards many of the aspects of the DMA. There is app sideloading, alternative app stores, alternative browsers, alternative payment methods, alternative hardware, license-free ports, and there are now more laptops than ever offered without windows. In the cloud, they have valid competition (Google, AWS) in both IaaS, PaaS and SaaS (Office).

Microsoft got regulated since before Google was founded (to put in context).