I do think 50's and early 60's song length for pop song to be the optimal length for songs.
When you have 1.5 minutes to 2.5 minutes and 3 to 3.5 minutes as a maximum and is pushing it.
I think core component of music composition/songwriting is that no music even pirated music is free. It cost time. Don't waste the listener time is the axiom of anyone writing music irrespective of genre.
It's part of the reason why The Beatles is my favourite band is that with the exception of Hey Jude (the repetition at the end is only part;y forgivable due to how transcendental the na.nanana part sounds) there is no wasted note and their songs is so compact.
the expansion of the pop song length to 3-5 minutes is one of the worst thing that has ever happen to pop music. Some songs justify that length but majority don't
I was listening to Off the Ground by McCartney recently and I think from a melody point of view it's almost on par with Classic Beatles however the difference is that it's less compact. There's only one song in that album less than 3 minutes. It's a victim of the modern age and why it's a 12/15 instead of 13 or 14 or 15/15 type album