People who never experienced high-trust and customs societies cannot grasp why and how it works infinitely better than low-trust ones.
But granted, all it takes is a few determined bad faith actors to break high-trust, when they are not vehemently and swiftly rejected…
But we have created an environment where this kind of thing is unthinkable, not even because people won't do it, but because they will only create legal trouble for themselves if they try. So the modus operandi for your average citizen in Western societies in general and US in particular is to not get involved and leave it all to law enforcement.
This is why some things can’t be found/bought without hetting the right path/contacts.
Contrast with the typical restaurant.
Moreover, trespassers, in addition to pursuit, often get flagged in a shared « do not host » book file across hotel lines.
The business can just make less money than they would if everyone paid (which is, as you say, impossible). Costs and prices are linked in some markets, but it's not a natural law.
I had a friend who worked at a gas station in high school. Filing police reports for people who filled up and left without paying was a standard part of operations.
This was in a nice area, too. Often people just forgot and drove away. They had recourse because they had security cameras and people had license plates. The cities where you’re forced to pay inside first probably have police departments that don’t respond to non-payment as gas stations.
If someone showed up with a gas can or something they were instructed to shut off the pump and make them come inside to pay. It wasn’t as much of an honor system as it seems if you’re not familiar with it.
You can’t have a pay-later business without an amount of non-payment, which has to be compensated by higher prices (which other customers shoulder).
These are all choices a vendor can make. Something like this usually lasts right up until the secret gets out to a wider audience where the people who don’t care about social norms have no problem abusing a system left wide open.