It's hyperbolic but Google has moved many basically-required system services into the Play Store, and they randomly push updates to them. A little while ago they pushed a broken Play Services update out to everyone on a friday night and it rendered a bunch of phones basically unusable. The only way to opt out of these consent-free updates is to disable all app updates, and then some things won't work. There's no way to uninstall those services.
Not hard to use that same update pathway to put a back door or snooping stuff into an update. (I find it unlikely they would, of course)
