Snap, Flatpak and/or AppImages?

[Linux for blind general discussion]

So it does seem then like appImages are the way to go. It sounds like we 
get the absolute best of every possible scenario in this seemingly 
antiquated but actually highly innovative portable app technology. Why 
oh why do we have people saying that flatpak is the future, or worse, 
snapd is the future, when we have appImages that are highly portable, 
and can even be sandboxed in much the same way, but are much more 
versatile owing to the portability? It's really nice to be able to put 
all the appImages I need on a USB drive and just use them on any Linux 
computer. I guess the one drawback I can see is the update problem, 
where most don't update themselves, but having repositories and appImage 
managers available would seem to resolve that issue, also in a highly 
portable way.

~Kyle