Please consider bringing back Customize.yaml UI.
As someone who don’t know much about programming or coding, yaml was and still is something I am not comfortable with. It is one thing if there is a way to see all the parameters you can set in regards to an entity and another to go in blind with a list of device classes spread over 5 webpages. My main concern with removing it is people who are starting out will have a lot harder time with some devices if the convenient ui is not there. I personally probably understand enough about HA to edit customize.yaml with ease now, however I don’t think it would be as easy for new people with no knowledge of this platform. Maybe hide it in developer tools or put a warning before you are able to access it if you are worry about it being used incorrectly.