If Microsoft wanted to be monopolistic, and it wouldn't be the first time, then why are they abandoning their strongest exclusives (Windows, Office) and instead enter a more competitive market, where Google, Amazon, etc... are well established and with no sign of letting go.

> why are they abandoning their strongest exclusives (Windows, Office)

They're abandoning the consumer versions of these, not the enterprise versions. The consumer versions are the competitive market, where they're competing against iPads and such. They're not abandoning Windows for businesses, Office for businesses, where there is still no established business end-user OS/office suite alternative.

Given Office 365 and day-one Game Pass release of all first-party titles, I don't think you need a tinfoil hat to imagine this.

I suspect lingering antitrust concerns are one of the few things standing in the way of locking consumer Windows updates behind a paywall, possibly alongside a "free with ads" version.