That's a local issue for sure. Not sure how, might be Firefox's fault in some way. But it's not just a combination of Firefox and Ubuntu. (I use Firefox on Ubuntu 22.04 and it's a couple seconds, maybe.)
That's the default install method for Firefox on Ubuntu, last I checked. I think they only recently had an apt repo too. I don't think it's specifically an issue with Snap either, nor do I think Snap is a terrible tool besides it being a centralized package store that you can't create 3rd party repositories for, though I understand people also complain about the block devices Snap packages add to your system.
Anyway, the intent of my original comment was just to say that they should do some more investigating on their issue because it's not as simple as Firefox in a Snap package on any Ubuntu installation.
