Slow train a comin'
[It's] a typical 1950s–'60s-period song because of its chord structure - George Harrison
All things considered Oh! Darling is not a great song. It's a fairly paint by numbers affair sticking closely to a cliched form (50's Fats Domino-style R&B) with few surprises. Even the previously mentioned bridge weirdness has been done before.
Every Breath You Take has an similar 8 bar bridge that starts on D (at 0:49), get back to A on the 3rd bar moves up to B and ends on E. It's possible The Police ripped off The Beatles but my money's on both of them ripping off someone else.
The melody in very uncharacteristically monotonal and limited in range (especially for the normally 'vertical' McCartney - see Ian McDonald). And the parallel lyrics (Ticket 24) render the song predictable rather than catchy. And I think I know why.
The song is so darn slow.
When she told him, she didn't love him any more, well, you know he nearly broke down and cried.
Let's pause there.
We know in the pit of our stomachs that against all good sense and lyrical craft he's going to inform us he also nearly broke down and died. We can see it rolling towards us like some ghastly slow motion motorway pileup. But it takes us a full 16 seconds to reach the point of impact. Then we have to head back to a verse which we've also seen coming a mile off. My brothers this should not be.
So the lesson is - If your song is really slow you need to put a lot of thought into avoiding cliches or subverting them. It's kind of like telling a joke. You don't want your delivery to be so slow that the audience figures out the punchline days before you get there. Unless you do something like this.
I had a dream last night that I was eating a giant marshmallow.
And when I woke up...
...my giant marshmallow had gone.
Thank you very much. I'm here all week. Try the veal.
(Sorry Paul, I meant quorn).