I hate web interfaces. They’re a necessary evil sometimes, but they don’t use paradigms that everyone knows and loves. For managing large amounts of structure information, nothing is better than a spreadsheet or text file as a front-end to a database.
JSON or YAML, I hate 'em both, but at least YAML is readable without having to paste it into a pretty printer. Oh, and you can comment it.
The biggest problems with web interfaces, though, is that you can’t tweak things that aren’t present in the web interface. You can, but you risk breaking things, because they’re not documented.
I’m wondering if I chose the wrong time to switch to Home Assistant. Having complete control is what interested me versus my current solution (paid, which doesn’t both me, but closed). Web interfaces take away that complete control.
Essentially, moving to a web-only UI is about taking away control from the user, plain and simple.