To play devils advocate, you could always buy from Hifiman. i find 90% of their cans light and comfortable for many hours of listening. I borrowed a friends H1kSE for a weekend. and used it from 10am until 5:30pm with no issues at all. light and comfortable, MAYBE got a tiny bit warm in the ear cups, but thats only natural since i only tool them off once during that period to eat lunch.for me at least it's simple: weight.
on occasion I spend several hours with headphone on, and while I really like how some of the Audeze headphones sound, I'd rather have no music than spend hours carrying those on my head.
also they tend to be expensive, which is obviously relevant to anybody on a budget. so maybe OP's question should be: why aren't all rich people with the neck of a bison, using planar?
granted, they are expensive but i find better value for money than Audeze considering Audezr is wayyyy heavier and has worse qc among their headphones.