Microsoft is trying to buy more than just Activision/Blizzard I the games industry.
With many games taking over 3 years now to make and about 10 of those Activision studios working on just Call of Duty, they have several more studios to go.
Sony’s acquisitions are less “egregious” as the companies they acquire usually generated few to no (valuable) IPs for their competitors - there are exceptions of course. That’s why most all of their acquisitions fly under the radar.