After creating a fresh installation of Ubuntu 24.04, I installed DEB Firefox from APT by following Mozilla’s instructions from here. But I noticed that it was secretly replaced with Snap Firefox. I was able to verify this by checking the About Firefox page. This is the third time I noticed this.
I swear it was the default already installed. Maybe I’m misremembering.
Mint never preinstalled the snap. They package their own version of Firefox. I believe they have an agreement with Mozilla.