I understand the appeal as the developer, Linux package management is heavily fragmented. The snap is build once deploy everywhere. But there are a lot of drawbacks for the user. I don't want my applications to be huge bundles that use twice the ram and have an alternate update system. As a primarily Debian user, I would much rather have a deb repo. If they insist on bundling it like this, flatpak would be a better choice than snap.
The snap identifies itself as an unofficial snap package of signal-desktop so my assumption is this is third-party volunteers repackaging it for snap users (and possibly non-deb systems).
