don't like Snap
I've been using Xubuntu for years, then recently tried MX and I've migrated all my stuff to MX. It feels nicer, has some nice tools and no snaps, it has a gui for Flatpaks too.
I switched to MXLinux (https://mxlinux.org/), which has XFCE as default DE. Based on Debian, with excellent default settings - after 3 months of use, it works very well.
Mint XFCE is very like Xubuntu, but it's a bit sluggish on my laptop. It feels like a scrubbed Xubuntu with a new paint job. I like everything but the slight sluggishness.
After removing the snap via sudo snap remove firefox you should be able to install the non-snap version of Firefox -
sudo apt install firefox