while I am no great fan of snap for server apps, it’s massively better than PPAs. First it does not interfere with system libraries, breaking dependencies and possibly other applications; then it has an easy way of reverting changes if things go pear shaped, an absolutely essential feature in this brave new world of constant updates and living on the edge (even it’s stable edge).
I think you can revert too using deb packages but it can be a pain.
The problem in this specific case is that the database update excluded the possibility of doing a snap rollback, a problem not caused by snap by itself, but by the way it was done at lxd level.
The alternative was risking it or postponing the dqlite update until a way could be found to make possible a useful rollback. The choice was made and the rest is history.