Arguably, Microsoft could do this as well without cannibalizing too much business. It's truly a shame they aren't doing it.

I wish they'd stop trying to use Microsoft Windows as an ad platform for all their other products and focus instead on making their existing OS better. If you want to advertise all your Microsoft products, here's a crazy and wild idea, do it on the App store for Windows. Stop making duplicated services too, we got Microsoft Teams which I don't mind, it seems really good, but what about Skype and MSN?

Sort of, but they seem to be selling user data trying to catch up with Google.

I don’t think there’s much revenue in it according to their 10Q, but all their releases send stuff to the cloud (Xbox, Cortana, windows10, etc) for things that don’t need to.

iirc, mozilla is doing this for targeted advertising in Pocket: they use client-side code to decide what to show.

Their web speech api is also focused on local processing, unlike Chrome, which uploads audio to a remote server for processing (afaik).