Since Ubuntu 22 they've decided to move Firefox to snap. Here's how to switch it back:

For Ubuntu 22.04, the empty Firefox Deb is pre-installed as a wrapper. You have to remove it via command:

sudo apt remove --autoremove firefox

For Ubuntu 22.04 LTS, the “Mozilla Team” team PPA maintains the most recent Firefox packages in DEB. Add it:

sudo add-apt-repository ppa:mozillateam/ppa

Set PPA Priority:

echo '
Package: firefox*
Pin: release o=LP-PPA-mozillateam
Pin-Priority: 501

Package: firefox*
Pin: release o=Ubuntu
Pin-Priority: -1
' | sudo tee /etc/apt/preferences.d/mozilla-firefox

Setup correct automatic updates, so that unattanded-upgrades don't overwrite our setup with snap:

echo 'Unattended-Upgrade::Allowed-Origins:: "LP-PPA-mozillateam:${distro_codename}";' | sudo tee /etc/apt/apt.conf.d/51unattended-upgrades-firefox

Install Firefox from PPA:

sudo apt install -t 'o=LP-PPA-mozillateam' firefox