A highly compatible design with no ads, unnecessary images, videos, animations, scripts that goes straight to point delivering you exactly the information you need and nothing else? Something that's easily accessible even with old feature phones allowing older people to get information easily?
Simply something that loads instantly and just works?
As a backend developer who occasionally has to work on the frontend, that top image is pretty accurate although it requires bootstrap smeared all over to pretty things up a bit. After that it will have the "Good Enough" seal of approval.
I do front and backend work. Biggest issue I see is people not thinking through interfaces properly (e.g. efficiencies & atomicity of operations), sanitizing inputs on both sides, error handling, and putting in the appropriate validation, authorization & testing.
A proper backend developer would have the query be a URL using the GET method with a parameter that the user can fill-in directly in the address bar and the result be a text/plain page with just a bunch of numbers separated by pipe characters (or an application/json page with that info encoded as JSON if you wanna be fancy).
This has the added advantage of working both for humans and as an API for use in machine to machine communications via HTTP.
As a full stack dev I'd like to say that the issue I see most from backend devs isn't a lack of styling, it's their need to wrap every element in 15 motherfucking divs. They don't seem to understand that most html elements are self contained and can stand on their own.