Having set up a Pi-Hole recently, I've had a similar realization, but for all of FAANG. I've noticed that the moment phones start getting used on my network, more than half of the requests made end up getting blocked.
Any stats by F A A N G? I'm guessing for me given I have a bunch of Apple stuff that one A is getting a lot of pings. The other A very few. I have a kindle but it's not plugged in and I haven't turned it on for months. G, well I use Chrome and many Google apps on iPhone. F, have FB and Messenger apps on iPhone but assume those are mostly isolated.
Unfortunately, it's not so clear-cut by looking at which domains are getting hits, but it would make a good weekend project. I'd have to map all subsidiaries back to their parents eg YouTube or IG, and then there's the trick of dealing with third-parties, like branch.io, who appears to be very popular.