You still seem to be taking a very non charitable read. I aluded to the browser, specifically because of the hard split between content markup and stylistic markup that is of very arguable benefits.
It is alluring. And when it works, it feels magical. Yet I still prefer TeX over many of the document systems I have been subjected to use. Markdown being a strong modern contender that embraced the ascii art nature of plain text files. Throw in the modern resurgence of jsx and the hard won separation of scripting from content is not even fought anymore.
To the ui/ux point, directly, I'm not even sure what you are arguing. The APIs that you list are all notorious for being bad leaking abstractions. And is why people make products over them, introducing new forms and functions for a different set of users. Just look at how you shoe horn shaders into those low level APIs.
But again, in the context of this story, I meant that you can't separate out the ui/ux concerns of a product completely from who owns that product. So, for AWS, they own both service and console. If one is bad, it is almost certainly from lack of prioritization in the team that owns the whole product. Often behind the guise of "this is not the architecture's concerns, but the front end."
Jumping to another metaphor to try and say it differently. In a bike, you can separate the drive train from the steering, but it will be a largely perspective based separation. Such that the entire bike is ultimately part of the steering and the power distribution. Yes, this is a simplistic look at it, but no more so than thinking you can fully isolate one from the other.
(Now, I do have to confess that Tufte is finally really resonating with me. And I fully agree that much of this is as useful as so many platitudes. Ask me about front end versus back end, someday. :) )