Yes. The software business requires fast feedback cycles.
Waiting for months for an uploaded artifact to appear on the channel would make that impossible.
> I'm talking about new packages here
Of course. Old packages usually remain on the channel and don't have to be re-uploaded in regular intervals or something like that.
> And even in the distributions which do offer to push applications between releases all the testing must be done in the open which means you can not really do a controlled beta-testing.
True. The beta testers select what they test, not the developers who tests their software.
That is indeed a difference.
> IOW: App Stores are more-or-less continuation of brick-and-mortar shops where developers and users interact with limited control by mediators (shop owners) while distributions put packagers firmly in control which means both developers and users are not satisfied and go elsewhere.
This is interesting and very welcome news to me!
All app stores I had observed so far did require pre-packaging, i.e. only allowed uploads of packages, making them equivalent to distributions repostories which also require the same packaing step.
Even worse, I had experienced situations where some target platforms required packaging even for local testing!
The only system that improved on that which I knew about was the OpenSUSE Build Service, which takes care of packaging and distribution and thus, as you said, only puts very limited obstacles between developers and users.
Good to know that some app stores have incorporated that now as well!