Until popular apps get removed from the App Store... and are put into their own stores or downloaded from the developer's website.
You can bet Meta will immediately put Facebook, Instagram, and WhatsApp in their own store... so they could put all sorts of data-stealing code in their apps since they don't have to be checked by Apple's App Review anymore.
Remember... Meta lost $10 billion when Apple introduced all their new privacy changes.
I imagine Meta's apps will be full of tracking if people can just download apps from their store or website.
That's what people are worried about.
😲
Digital Markets Act (DMA), also consists of a provision that any company, including Apple, cannot steal user's data or combine data collected from two different services belonging to the same company. Apple's advertising identifier, that spans across the device may become illegal perhaps, as it allows combining data across the entire device? Not sure about the last one though.