So...comfortable and practical?
People don't want to do laundry on their vacation. And unless you're rich and have porters lugging around massive luggage with carefully packed fashionable clothes, people are also space-constrained
So, they optimize for comfortable, quick-dry, wrinkle-free clothes so they can maximize exploration and energy.
That's......what you have to do when you are spending your limited vacation time to see the world.
Part of this is definitely a snobby european mindset. Europeans get 5-6 weeks of vacation a year, and burn 4 of those on August so they are used to LOONG consecutive getaways, and structure their lives accordingly.
The rest of the world (And I don't mean America, I mean the entire rest of the non-European world) doesn't have that luxury.