Seems overly complicated if the goal was a "simpler fortune" - a self-contained shell-script is perfectly capable of echoing random lines (I should know, I had one for generating email signatures).
On the other hand, if all one wants is a set of fortune cookies - there's no need for the new client - fortune-mod exists:
That said, I appreciate a trivial rust program that does a simple job - as someone not quite having taken the time to learn rust yet?).
I would probably not bother with the built-in cookies - if anything - have an option to "seed" ~/.config/friend/fortunes.txt or whatever is the proper xdg path.
On the other hand, if all one wants is a set of fortune cookies - there's no need for the new client - fortune-mod exists:
https://www.shlomifish.org/open-source/projects/fortune-mod/