The containers do not restart when the snap package is updated.

If snap decides to update lxd on the nodes of your lxd cluster at the same time that a node has failed it is a CF.

The cluster will not come up because your down node is now not the same version as the other cluster nodes.

> an app quitting out from under me because it wants to update

This doesn't happen, at least on account of Snap. It's copy-on-write when it comes to updates, and whatever version you have running at the time of update will happily keep on running. I've been mildly confused by this a couple times, when I would end up with two different versions of VS Code running side by side, but the bright side was that my work wasn't interrupted.

It incidentally also sidesteps all the problems that stem from libraries or configuration being updated under a running application, which can happen with Apt.

Especially when they're being installed covertly through APT

This is sort of like saying you can turn off auto-updates by leaving your Internet connection disabled - true, but missing the point that what people are primarily complaining about is having to adopt an adversarial relationship to the software they use.