It depends on what you'd consider "untrustworthy", but some (myself included) feel it's hypocritical for Apple to position itself as a privacy conscious choice, and use its marketing / PR machine to give the impression it only makes money on devices/subscriptions, when they're silently managing an ads-funded cash cow, with billions of dollars that go directly to the bottom line, as pure profit.
Here's a few pointers, to get you up to speed [1-5]. Of course there's nothing wrong with monetizing their own user base and selling ads based on their 1PD (or, in the case of Safari, monetizing the search engine placement). But I find it ironic that they make a ton of money by selling ads based on the exact same practices they demonize others for -- user behavior, contextual, location, profile.
[1] https://searchads.apple.com/
[2] Apple’s expanding ad ambitions: A closer look at its journey toward a comprehensive ad tech stack - https://digiday.com/media-buying/apples-expanding-ad-ambitio...
[3] Apple’s Ad Network Is The Biggest Beneficiary Of Apple’s New Marketing Rules: Report -- https://www.forbes.com/sites/johnkoetsier/2021/10/19/apples-...
[4] Apple Privacy Suits Claim App Changes Were Guise to Boost Ad Revenue
- https://www.hollywoodreporter.com/business/business-news/app...
[5] Apple is becoming an ad company despite privacy claims - https://proton.me/blog/apple-ad-company