And you still have to pay both of those if you're on vacation. Unless you're suggesting that people pack up everything they own, move out of their house, and go on vacation for a month?
I know tons of people who worked minimum wage jobs who saved up and packed up and went on vacation for a month somewhere where the basics are much cheaper than back home - e.g. a hostel in Thailand while living off street food.
I did it too.
If youre the kind of person who flits between luxury airbnbs and cruises then yeah, "travel is a luxury".
There's people that rent out their house a la AirBnB, while out on a month+ stay in a LCOL country. And in some cases come out ahead doing so, while having a vacation.
Of course it varies from household to household whether it's practical (or wise) to do this.
I have previously rented my house out on AirBnB, and it's not a switch you can just flip when you feel like taking a vacation; there is a lot of work you have to do to get your house ready to rent, and you have to establish (or maintain) relationships with people who can handle turnovers and other on-site services. A month would not be long enough that I'd feel like it was worth the hassle.
Staying at home is also increasingly unaffordable for a lot of people in the United States, of course.