Rotary phones in escape rooms are sort of a running joke. They are period-appropriate for a few decades of history, but for those who don’t know how to use them… they are completely unintuitive.
It turns out that they weren’t exactly intuitive when they were released either. Here’s an infomercial from 1936.
The biggest problem with the rotary phone interface is that it doesn’t do much to imply its own usage. It’s truly designed with the assumption that the user will be taught how to use it.
If you want to see this in action, give this Kids React to Rotary Phones video a watch. It’s adorable.