The only use case for Appimages
If users want to carry applications around on a thumbdrive, or run on a fully immutable system like TAILS, Appimages may be needed. But this is the only target, and it is not a standard use case.
I guess I agree. This is precisely the case where I have ever used them. Namely to have a portable executable of my password manager on a stick together with a backup of the password database.
I had no idea they were being used elsewhere.
You always have to be prepared for that. This is Arch.