No variety of any language is superior to another
It's not even a UK vs USA thing - for me (a Scot) I notice that large parts of southern England have appalling pronunciation ("fing" vs "thing", "bovver" instead of "bother", pronouncing "r" like "w" - see how the guy on the right pronounces "presentation" as "pwesentation", and "Ryzen" like "Wyzen" here: https://www.youtube.com/watch?v=lP2QkBnRqko), and that's the most populous region so much of our TV would also be no-go for English learners.
If there was a revolution and the residents of liverpool became the new ruling classes then pretty quickly that would be the "correct" variant and the queen's English would be the "appalling pronunciation".
Yes. This is about people wanting to improve their english. They have identified that their english is less than they deem acceptable. If you want to improve, you need something to aim for. So that does indeed mean putting one version over another.
The guy in the video I linked is actually an excellent example of the "professional class", and should by conventional wisdom be the kind of pronunciation you should aim for ... but you'd be entirely wrong to do so.
As to why these sound wrong to me, I'm from an area that is looked down on accent-wise and is sort of the subject of ridicule (usually just for fun). Since I moved abroad and mix in pretty multi-cultural circles I've seen first-hand what non-native-English speakers have trouble understanding when they talk to an English-native speaker, and I've often reflected on what caused this. One thing that surprised me was how easily my fellow Scots have been understood and how much difficulty people had understanding the English, since I was always led to believe that we are the ones who talk incorrectly. And it was this that made me realise how their pronunciation can stray far from the supposedly correct one - I gave a couple of examples to demonstrate this. There are plenty more if you listen carefully. The "how do you pronounce..." part of the NY Times British & Irish accent quiz was really quite good at illustrating this: https://www.nytimes.com/interactive/2019/02/15/upshot/britis... (door/poor, farm/palm, horse/hoarse from there are nice examples).
So yeh sure, nothing is "wrong" in English and all that - there's no central authority that should dictate this. But when it comes to accents and clarity not all is as it might seem at first blush.
Further to this, I've also worked on my diction using a number of available resources such as https://www.audible.com.au/search?keywords=get+rid+of+your+a... .
I could never fully appropriate the Australian accent, but something more akin to British becomes non-determinate and easier on the ear (ref: how people prefer speech synthesis in a different English region to their own).
It kind of surprises me that more non-native English speakers don't do the same; I have worked with people who I've really struggled to understand. But I can't really tell them "can you please work on your accent", as much as I wish I could and I knew it would serve them well.
By watching Archer you might also perhaps, better understand when things are phrased inappropriately?