https://wiki.debian.org/DebianInstaller/Preseed
Quite different than bootstrapping a system as described in the OP, but relevant in the context of your comment.
Mostly sets up repos, installs packages, does some basic configuration. But also calls a bash script that sets up KDE/Gnome, down to the launcher icons, widgets, themes, a wallpaper, and application settings.
Basically "cattle not pets" approach to workstations and laptops.
The only thing I struggle with are Firefox extensions. The last time I checked automating them was such a drag. Surprised there's nothing like apt or dnf for them.
https://pyinfra.com/ https://stackoverflow.com/questions/37728865/install-webexte...