Watch a number of “the hated one” visa on youtube. * disclaimer could lead to serious depression, you have been warned. TLDR- nothing is ‘more’ private than the other, just lots of marketing and smart legal speak to sway the sheep to one brand or the other.
This is a cool question because it gets into some deep nuances. I’m no authority, I have not packet traced, mapped, decrypted etc to see what gets sent to where. Just from tech enthusiasm I can regurgitate an opinion. “choose your type of privacy”.
I have the feeling apple is only private in that they have figured out data is the new oil (taken from the literal URL). They will eventually become a data broker themselves, having learned why let others do that via our devices when we have such control of our devices? So maybe more private in that Apple will be more discerning/expensive as to who gets to buy that data.
hackability. They (apple) like to say they are more secure. From marketing it would seem they are for normies, and for advanced users Android can be made more secure and for high value targets, you are pwned regardless, just embrace it. It gets kind of annoying the tick-for-tat bank malware that is just for android, then there is one for iOS, then there is a critical zero day for one, then a week later, the other.
As a listener of the Privacy, security and OSINT podcast the owner/speaker has bounced around- I believe he went android, then apple, then back to android- For sure the last two steps have happened. He has dabbled with CalyxOS and Graphene OS and has the pros/cons in his podcast. Also in his podcast is the common sense usage cause one ROM or another isn’t just a blanket “more private”. As @MazeFrame points out, if you are leaving services on, hitting low power BT as you walk around, wifi hitting APs etc you can somewhat defeat the purpose. Yeah a ROM can cut off all google APIs so that data isn’t being sent to google directly, but there is such great effort into big data analytics that the APs and low power BTs that got your MAC, UID etc are still forwarding to big data platforms and figuring out who you are, where you went, what you were likely doing etc. All this data gets put into the open market and aggregated by even bigger companies.
Honestly I feel privacy is dead- regardless of platform you use. Unless you are willing to go pretty extreme and hire services from people like that podcast I mentioned, and then also getting a plan and policy in place from them… AND willing to stay informed and keep up with the ever changing climate and tech.