Fair points
PeteHski As a non-competitive cyclist I'm not chasing seconds on segments but I do like to put out hard efforts on occasion. A light bike feels better and more responsive. On the hills I'm suffering too much to notice but I do notice it more on stop/starts and accelerations. When I first got my Guru Photon it came with tubulars and the whole thing was 13lbs and it felt unintuitively light. Riding it was like riding without a bike (if that makes sense). That was a point of revelation for me, I understood then why "weight weenies" is a thing (not that I'm a weight weenie). My point here is lighter may not be better objectively (but it can't be worse), and subjectively it matters to the overall riding experience.
Fully agree modern bike are smoother, faster, more comfortable, have better geometry even. The closest thing I have to a modern road bike is my 2015 Trek Boone. It's technically a CX bike but the geo is pretty close to road geometry. It rode like an anchor despite being carbon and having a 34x32 climbing gear. It came in at 21.5lbs and I have since upgraded to carbon hoops and different cranks and now it's fantastic (probably at around 20lbs now). I've not taken it on climbs or hard efforts yet but look forward to seeing how it compares to my yesteryear road bikes.