I don't know if it's still this way, but a decade and more ago (when I last had any professional contact with Microsoft's development) the company was effectively divided into two competing factions- the Office people and the Windows people. They had wildly different priorities for the shared tech stack, and mutually exclusive demands on the others' products, and there was a constant bun fight on who got their way. The surprising thing is, even by that era, the Office faction were the dominant one; that's where the real money was.

Then I gather the Azure faction was born and has completely dominated both, becoming a massive majority of the company's profitable business.

The gaming people (Xbox and whatnot) were always poor relations, if you're wondering, and MS R&D was its own eccentric little world which seemed to exist entirely outside of the universe inhabited by any of the others.