You're cherry picking. They built Windows. They built Office. They built Azure. Windows Phone (RIP). Exchange. Sharepoint. Visual Studio. Bing.
Every big company has a raft of acquisitions in their history and if you really want to you can draw a tenuous line between an acquisition and a subsequent product line. The claim that Microsoft "fundamentally doesn't make anything, they never have" is just silly.
Office started as MS Works, which was a continuation of an Apple product by ex-Apple employees.
https://en.wikipedia.org/wiki/Microsoft_Works
> Microsoft Works originated as MouseWorks, an integrated spreadsheet, word processor, and database program, designed for the Macintosh by ex-Apple employee Don Williams and Rupert Lissner.
Modern Windows was fractions of OS/2 (failed partnership with IBM), ex-DEC folks made the kernel (Win 9X is a failed lineage) and MS copying the Mac.
Your examples while grand, don't paint a picture of a company that does a lot of in-house innovation. You got me with Sharepoint, something to be proud of. Oh and Teams.