As far as what we actually wear, maybe we're smarter than we were, OR we're more attached to our comfort. 30 years ago I could fight hypothermia or heat-stroke much better than I can today ... and my first few jobs, it didn't matter what I looked like when I got to work, so my gear didn't matter as much.
Today, I don't have to suffer; I have the means to buy decent equipment (for safety if nothing else) and it's available anywhere. So why suffer?
That's my take, anyhoo.