Aside from easily rolling out (parts of) my home automation to multiple environments (like my parents home, office, etc). The real use case for non-UI first is that with home automation software you often have to roll it out on the _same_ environment very often. Be it a corrupted SD card, broken state after software update, database bit rot, hardware RMA, etc, there are many reasons state gets corrupted or lost. So you either need to rely on a backup (if possible and hope it's up to date and works with the version you have installed) or configure everything by hand, again and again and again, via the UI, step by step, hope you don't forget that one setting you didn't write down. I rather have my home automation setup be build and deployed reproducible from a (VCSed) source.