One thing that I notice that seems to be kinda lacking in modern popular music... are songs with long, minimally repeating type melodies, where the entire song at least *seems* to be heavily dictated by the lyric and melody.
Some Bacharach and BeeGees stuff comes to mind. Plenty of classic songs really, too many to mention probably.
As opposed to a type of song where everything hangs more on a couple juxtaposing grooves/chord progressions and driven by them, and melody seems to be more tacked on top.
A very good point, and a difference in writing methodology explains this, in my experience.
I still most typically have always written "the old-fashoned way", i.e. at a piano or guitar, crafting the harmony, melody and lyric more-or-less together as a whole. But that makes me an outlier in my age group.
One thing I struggled against for a long time is that songs I wrote with this process tended to present as "old school" almost regardless of what ended up happening in the production or arrangement. You can tack on every "modern" trope and remove every 'traditional' instrument, and it won't make it sound "modern."
However, on the occasions that I've written to tracks made in advance by others, the opposite is true: the result ends up being much more "contemporary sounding" even if the track itself is self-concsiously "retro" (and even if the GOAL of the writing is 'retro').
the more-typical modern process isn't inherently "worse," or anything-- just a different sort of result. The restrictiveness of the pre-existing track, groove, harmony, tempo etc. enforces a certain boundary. This limitation can sometimes foster some real creativity (as limitations often do). But even outside of anything qualitative, assuming total success using either methodology, the result will be palpably different.