While I get that some stories use the premise "what if X didn't exist or what if Y did" just as a means to explore the meaning of a thing with the protagonist, I kind of get a bit annoyed when no work is put into the world building of this new world to explore the consequences of this change.
For an example of this, we'll look at the 2019 film Yesterday, where luckily one of the posters explains the premise quite simply.
Essentially, a failing musician who mainly does cover songs of much older artists is somehow sent to a world where he's the only person (sans two elderly fans we don't meet until later in the movie) who remembers the Beatles' music.
He uses this music to become instantly famous (evidently the music is still one mega hit after another in this alternate 2010s despite it referencing the USSR and such), but is immediately stricken with guilt despite an elderly, living John Lennon confirming that he NEVER formed a band with the others, and ultimately releases all the music and lyrics to the world due to his feeling bad about plagiarising people with no memory of having created the songs in the first place.
Now, this movie is primarily for British people of "a certain age" who think that the Beatles were the best thing ever, and are confident that everyone would agree with them if they heard them for the first time with no context (a fact obscured by their having an admittedly great late-20s Himesh Patel in the lead).
However, it runs into the same problem as the show Peacemaker had when the hair metal bands and such that the title character listened to in a version of our reality still exist in the alternate reality he travel to where it turns out the Nazis won the war (he doesn't notice until days later, because he's not very observant).
Just saying, if something that massive happened in the US in the 1940s/50s, a good chunk of the history of music in Jack Black's School of Rock diagram would be erased due to both the Nazis and their American sympathisers (like Henry Ford) loathed the African American genres that would later develop into rock music.
Just saying, just as how in Peacemaker the shape of rock music would have been drastically changed by the Nazis conquering America, it seems unlikely that British pop music (or pop music in general, considering the amount of American imitators that spawn from their success in the States) wouldn't have also been changed (albeit not to as great degree, although I guess Paul McCartney wouldn't have done the theme song to Let and Let Die in this reality) dramatically by their not existing?
Again, the butterfly effect of the Beatles not existing isn't the point of the story (seemingly Coca Cola, cigarettes and Harry Potter also don't exist but nothing else has changed either), but the fact that it's not a factor REALLY BUGS ME.
The show the West Wing has a similar issue, where the premise for the show was, after the scandal-ridden Clinton years, what if The Ideal (Centrist, Neoliberal) Democrat was elected president as a kind of wise philosopher king. But contrasting with the 2006 British show The Amazing Mrs Pritchard (which took the idea of an independent candidate becoming prime minister and reacting the era of Blairite New Labour by swinging for the fences with policies like moving the capital from London to Bradford to stimulate the economy of the North of England), the West Wing was stifled both by the writers being much more conservative than they themselves realised (Bush era Republicans are considered more agreeable and honest than any progressive Democrats, trade unions are portrayed as a nuisance etc) and a desire to keep things close enough to our reality to comment on contemporary politics (the equivalent of 9/11 was committed by American white nationalists in universe, but somehow the US still ends up in the War on Terror in the Middle East, with the "wise philosopher king" president making unhinged comments about wanting to bomb Mecca) prevented them from really doing anything interesting with the premise.
