Earlier quoted context omitted.
I can see why Snap is like it is from Canonial's perspective - but from the User perspective it seems like FlatPaks[1] are much better and address the issues that this article raises [1] https://flathub.org/home (Disclaimer: I'm talking in a personal capacity but the company I work for in my day job now owns Red Hat - I don't work on Linux Operating Systems).
Every attempt at "solving" this "problem", including Snap, Flatpak, and AppImage, are an absolutely awful regression in the state of Linux. I absolutely hate this trend. These tools solve problems for only two kinds of software: proprietary software, and software with suck reckless, runaway complexity that it can only run in one specific environment. I have no interest in either kind and I will give no quarter to "so…
However, ignoring the aspect of software distribution, wouldn't you agree that the approach taken by the Linux desktop today is deficient security-wise? For example, I would like to be able to give mbsync (or Thunderbird or whatever) my IMAP password without giving it to any other program. So I don't want to store it in mbsync's config file in plain text. Neither will I use gnome-keyring (or any other keyring) because it doesn't have any kind of "program authorisation". Any program can just spawn a new "secret-tool" process and get my credentials from gnome-keyring.
I've been thinking for a while about implementing a keyring which runs as a daemon with SUID of a dedicated user and checks which program sends requests to it, using /proc/pid/exe, but I'm not sure if it's a secure source of truth: how e.g. namespaces affect what's visible in /proc/pid/exe. I know you've been developing himitsu[1]. Have you thought about this problem in that context?