Earlier quoted context omitted.
As a user I don't like neither Snaps (that for sure as this is Cannonical only) nor FlatPaks (as they seem conceptually a "80% solution" which combines the problems of package systems with the problems of self-contianed apps, but don't improve on anything). For me the only acceptable solution besides proper .debs are AppImages. AppImage doesn't try to "replace" the package management for desktop apps like the former…
I tend to agree with you, but I really like updating all my software with one click/command. So out of curiosity: My application is already self contained and statically linked, so no AppImage needed, but it behaves like one, you can just run download and run it everywhere. And so what you're describing will be for sure an option for those who like it (in fact currently it's the only option in alpha). How would you l…
However, you could also include a facility to manually check for updates and either self-update or just show the changelog. Why manually? "I know you're about to do this thing real quick that needs to get done, but a new version is available! Would you like to twiddle your thumbs for 5 minutes while watching a progress bar?".