This is neat and interesting, truly, but the classic “what now?” emerges. I guess the only answer is “throw out my iPhone”? Otherwise this kind of seems like a circuitous ad to make people get worried and download Psylo, which I see has in-app purchases. I’m not trying to come at you here, but it’s just hard not to feel suspicious online these days.
Don't install apps outside trustable apps that don't embed tracking. Even if you cannot uninstall every app, the fewer you have, the less cross-app tracking. Also donate to and consider installing privacy-conscious alternative phone OSes. They may not have closed all holes (yet), but at least their incentives are aligned with yours.
The only way to prevent this right now is to avoid installing apps that are doing this.
Apple has been very good about public perception of its products and privacy. They just spent a lot of this year’s WWDC talking about the latter so I’m sure someone at Apple is aware of this.
I have not spent a lot of time thinking about why certain things like 50 apps install queries, boot volume timestamps, etc are provided to developers. But I think Apple will close these loopholes.
Also love the idea of outbound network connections being disabled by the user per app