as you need to be logged-in to use the service and make payments, there’s not much difference to using the service through a regular Android phone. Maybe some upside in less trackers / Ads.
At best it works, at worst digital rights management doesn’t like the /e/OS Android and there’s no playback / download of files.
It is not anonymizing in any significant way, but it won’t collect, use, or re-sell your data as much as “regular” Android or iPhones do (at the operating system level). Apps will work as expected in almost 100% of the cases, including subscriptions and online payments. I think apps that needs to communicate with the parent company to work still does that, but it might be some filtering on the amount of data that slips through. Personally I always try to download my apps from the F-Droid repository, they are open source and almost always behave nicer than apps from the Google store.