Shopping apps aren’t really needed, I mean people could use the websites instead
You could say the same thing for probably half the apps in the app stores, and yet people keep installing the apps. On iPhones, I think part of it is the fact that iOS had such poor support for PWAs.
The EU has ruled that this isn’t sufficient and that people shouldn’t have to pay for privacy.
Of course, companies in the USA won’t care, except for customers in California (thanks, CCPA and CPRA).