Would this work without the Beatles' songs?

Rating: 2/10 (20 August 2019)

Short answer is: no it wouldn't.
Spoilers ahead. You have been warned:
Two sentence plot summary: A unsuccessful musician gets thrown into an alternate universe (without any explanation of how and why) where various (pop-culture) things haven't happened but almost everything else is at is it today: Among them Harry Potter, Oasis, cigarettes and the Beatles. He recreates the Beatles' songs as his own, becomes famous and almost doesn't get his girl (but of course comes clean very publicly and gets her in the end).
So what do we have here? A whole bunch of problems.
The problem with the plot:
It's lazy writing from A to Z. You know: The type of romantic comedy where the two fated lovers cannot confess their love for one another over a huge amount of time (and 2 hours of movie-time) because people are interrupting, phones are ringing and doors are knocked on. In the end the guy gives up fame to get his girl. Original? Not in the slightest. Even the universe-shifting at the start merely exists to string scenes together in which Beatles songs can be played (and then mostly only fragments thereof).
The problem with the actors:
The protagonist and the girl are likeable enough. No one else in the movie (apart from the two who also remember the Beatles) is. Kate McKinnon doesn't ever seem to catch a break with the lousy scripted stereotype characters she's handed - and this movie is no exception, making her play the standard money-hungry agent. Most of the side-characters are only there for the "cringe-humor". The drug using firend. the fake fanboi-friend, the father, the mother, the neighbor, the list goes on.
The problem with the humor:
It feels like the movie desperately tries to put in a funny moment her and there but this basically boils down to the protagonist finding out that X isn't there in this universe, googles it and finds something else unde the same name. Calling this a RomCom would beg the question: "What comedy"? The theater was reasonably full but there wasn't a single laugh. A few isolated chuckles was the best it ever got.
The music:
The movie very heavily relies on the recognizability of Beatles songs. Which is to say: The music - when it's a Beatles song - is great. Any other time it's 'meh' at best (and the recognizability of Oasis today is more of a: Oasis...who?). And here is really where it all falls apart. If it weren't for the nostalgia (i.e. if the Beatles were replaced with a fictional band and fictional songs) then this movie would be utterly boring to watch.
2 Stars for the Beatles songs. Zero stars for anything else.