Android 12 was what fixed what I meant to refer to: unattended updates with third party sideloaded stores. It's from 2021 and probably didn't get 50% marketshare until ~2023 or so. Developers for those app stores had to deal with their users being out of date all the time to a much bigger extent than Play store and officially partnered stores.

And Android WearOS is still hard for side-loaded stores to work with at all without developer debugging mode I think and is tightly integrated with the phone stuff.