The startup times are ridiculously slow (multiple seconds or even worse) at least on some machines (I've only ever experienced them to be sluggish, but some people say the opposite, so...) and this is particularly egregious for e.g. firefox or a password manager (bitwarden).

Because I just couldn't bear it anymore I uninstalled the firefox snap and installed the flatpak instead. Flatpak solves similar problems, but doesn't seem to be as sluggish, at least for the applications I've used.