The saggy pants thing started when I was in high school in the early 90s. I always had the exact same question you wrote: how in the world is that comfortable? I know it's an inclusion thing. Your group does it so you do it. But still... I would think basic comfort would win out. And adults these days who still do it, they don't have the high school group thing to excuse the behavior. It just baffles me. And it really baffles me that 30 years later, it's still a thing.

I've seen the pajamas thing on youtube and heard about it from friends. Luckily, Japan is still fairly formal when out and about. Women are still stuck in the 1950s where they feel the need to put on skirts, do their hair, and wear heels when they leave the house. Men are growing more casual, but still, nowhere near as casual as people in the US have fallen.

I blame the social media and the algorithms. Everything thinks they are the main character now and no one else matters, so their own comfort is the only thing in their mind.