Like others recommendations here, I also switched with fresh installation of Debian. If you don't do this you would end up with broken system and also you would not see what all debian has to offer.
I think in theory at least if your username is anthropodie, you should be able to copy /home/anthropodie to an external hard disk just for backup, install your new distro, set up your new user and copy your user home directory back. Anyone tried this?
It would be slightly more work involving parted (or whatever partition manager you prefer) to create a new partition, resize existing partitions, etc., but quite doable (if tedious and time consuming).
/home is kept intact. After installation of apps on new setup I don't even have to configure them most of times because they can find their config directories in /home/myuser/
Instead I backup my home dir with borg backup to drives/cloud.
I have a script to borg mount my most recent borg backup, so when I set up a new OS install, I just run the script and copy my files over from my backup to my computer's SSD.
I love this method because I can easily install a different SSD, switch to a new computer, or just do a clean OS installation very easily.