Not every applications uses dotfiles to store settings...

And then you have dotfiles which store a unique id so anyone you share it with has to dig into it and tweak things...

That’s fine for techies, not so much for everyone else.

Dotfiles aren't enough to fully describe a system configuration, though. I'll regularly use both CentOS to Ubuntu, and both the available configuration tools and default services (along with other differences like SELinux vs AppArmor) trip me up more than I'd like to admit.

Seems like a possible future use-case for systemd's homed. Maybe there will be a utility in the future to help setup configuration. 1 internet point for the person whom implements it first.