That's fine yeah but sometimes you want a truly clean setup. Basically using it as an excuse to get rid of stuff you don't need.
For example, I use https://www.chezmoi.io/ which creates a standard home directory set up (prompt etc), decrypts SSH keys and other private stuff, and installs a bunch of tooling through brew/apt.
The “clean install” thing is a habit from when old Windows would have phantom issues if you didn’t start over every so often.