It seems to me that, with the exception of a rogue employee, all of those examples are at a greater risk of occurring with a small, independent provider. Google almost certainly has more security resources, more legal resources and political clout, and isn’t likely to be acquired any time soon.
I can’t say I love having Google track me, but I don’t feel any better about someone else doing it either.
If the marketplace was full of independent trackers (which I'm not suggesting is a good idea, because third party trackers are bad in the first place), then as they get compromised, only a small subset of data is lost... The chance of losing everything or enough data to pair to your real identity is a lot lower. It's like IDs in physical activity. If you visit your bank they track you by a different id to the library, your medical record, etc, each might be lost individually and be upsetting, but do they reveal data about all the others? No.
Why is Google security better than anyone else? Monopolies often have more resource, but lack motive, because they are a monopoly. Without transparency we have no idea how secure Google's systems are, but we do know Google has been hacked before.
I can’t say I love having Google track me, but I don’t feel any better about someone else doing it either.