Absent considerations about identities being stored by third parties, what is the downside of targeted ads? I found myself wishing for more targeted ads after listening to yet another random fast food ad the other day.
IMO the problem is not that ads are better targeted, but the fact that they exist at all on the OS (let alone an OS I paid money for). Microsoft is truly cancer.
The fact that the targeting part is the output of a multibillion-dollar industry focused on scientific experimentation on humans without informed consent.
Also the fact that they're ads. That's a problem, too. Basically the whole thing is one big downside for everyone who isn't in adtech or trying to sell you shit you otherwise wouldn't buy.