Also to consider: Wifi networks are used for tracking. Google and Microsoft offer methods for disabling this for the network that you control. (_nomap/website) Apple does not. Also Google makes it not impossible to stop tracking ( F-droid/Netguard/Superfreezz) on your phone. Pro iphone: Apple does not share access to an advertising id for monetization without user consent. Apple guards application boundaries.
I believe most of it is actually Mozilla, and not either one of those companies. Looking at DNS lookups, 2/3 of all DNS requests on my network go to location.mozilla.com