I dislike the idea that Apple has allowed Google to be its search engine by default. However, for the other data, it is pretty private and secure.
Secure Enclave stores keys (256-bit) that manage sensitive data such as passwords, your credit card used by Apple Pay, and your biometric identification to enable Touch ID and Face ID. This makes it harder for hackers to gain access to your personal data without your password. These keys are unique to your device and they’re never synchronized with iCloud.
Your health, iMessage, and Home information are end-to-end encrypted through iCloud. Only you have access to that information on your devices.
Apple makes it pretty easy on what you want to personalized and what you don't. It's just a matter of delving into the Settings App.
Of course, none of what I mentioned matters if anyone reading this is a conspiracy theorist, an Apple Hater (though I don't know why you would be on this thread) and or fully skeptical of everything.