Google and Apple are both heavily invested in ads (apple made 4.7 billion from ads in 2022), they have a track record of exfiltrating your data (remember contractors listening to your siri recordings?), of lying to the customers (remember the home button scandal on iPhone?), have control over a device that have your whole life yet runs partially on code you can't evaluate.

Trusting those people makes no sense at all. You have a business relationship with them, that's it.