It makes less sense since extensions actually ran on Android, e.g. via Nightly and creating your own list of exceptions. Also if you downgrade and install in an old Fennec version, extension will continue to function if you then update to the latest.

I think the move was an attempt to create a walled garden. But for whatever reason, they have now decided against it. Thank goodness.

Which I think is kinda weird decision since they could've just hidden a setting that unlocks all addons in the options. But maybe they were so incompatible at the time that it wasn't worth the headache.