In my case, I use several different types of machines: Personal Linux desktop, personal low end Linux laptop, remote servers where I have sudo, work Mac, shared remote work servers where I don’t have sudo. I want my setup to be basically the same everywhere so that my muscle memory works, but there are some things that also need to be a bit different for each. Hence, a dot files manager that lets me run one command to keep my environment consistent in all those different targets. I use chezmoi + git for it nowadays.

It doesn’t have to be a big baroque thing. When there’s a dotfile I configure regularly, I move it to a Git repo and use stow to put it “back” into place with a symlink. On new machines, it isn’t long before I try something that doesn’t work or see the default shell prompt and go “oh yeah, I want my dotfiles”, check out the repo, run a script that initializes a few things (some stuff is machine-specific so the script makes files for that stuff with helpful comments for me to remember the differences between login shells or whatever) and then I’m off to the races.