Generally speaking yes you wipe your partitions and start over and restore selectively from backups. I recommend backing up /home and /etc (and maybe /boot) and test your backups by stimulating a restore (e.g. to a dir at /home/restore, just see if it is the right size and has your files). If you don’t have a regular backup system, this is a good opportunity to start using one. I like borg-based tools and filesystems that can do snapshots. Then you just make a backup right before you install the new distro, then restore from backup.

You can also start putting /home on its own partition in case you swap distributions often but I’ve never found this appealing. It’s also not a replacement for proper backups. I do set up /home to be discretely snapshotable, though.

Why are you looking to change from Mint? Mint is pretty nice, though I prefer Debian for that kind of distro. I’ve been trying out guix and really like it, though it’s definitely a power user / dev distro, as you have to configure your system using a dialect of Lisp (a programming language).