I also wonder if there's a element of tools and training.

Modern CAD tools have been horrible at "fiddly" ornamentation for decades compared to a hand drawn decoration. There was once an article about this but I can't find it now.

And then when architects spend careers building cubes and angular slab-sided and regular shapes they don't train their apprentices and juniors to be able to conceive, specify and draw a pleasing ogee and a proportional scrollwork around a window.

And there's definitely an element of can't-be-arsed about things. Riffing on your clothing example, I have an, IMO, outrageously expensive designer hoodie I was once given. It quickly failed because the kangaroo pouch was just sewn onto the single-layer front with no backing to reinforce the corner. Instant hole. Though there's some element of survivor bias there, as all the real shit from the 1920s fell apart immediately too, so it's not that everything was great.