Not so much proprietary software (those dependencies would be owned by Canonical and therefore released in the same lot) but I understand there is considerable dependency on deployment machinery. Documentation for that machinery will need to be split out into private (contains secrets, references to customers, etc) and public (consumable by someone looking to replicate a Snap store deployment) and so on.
> Rather than trusting software because it has verifiable source code, we now trust software because it came from a store that removes well known malware.
The world has moved to that. I don't like it. I would prefer to install only distribution-curated software. However that doesn't help me get a bunch of software that isn't available that way. Where it is (and at the version I need), I use it. Note that this particular statement of yours applies equally to AppImage, Flatpak and everything else that isn't distribution-curated. It's not just an argument against Snaps.