Not to mention that sideloaded apps are still checked by Play Services on Android. Sure it is certainly more risky than the manual reviews done on the play st

Not to mention that sideloaded apps are still checked by Play Services on Android. Sure it is certainly more risky than the manual reviews done on the play store, but that's a weak argument for disallowing side load. Especially as the OS does it, with a huge warning telling you that it is less secure. I have had to deal with Apple reviews for a long time, I am absolutely convinced that blocking sideload on iOS is 99% a business decision, not a security one.