This website says international moves cost "up to $2.5k". Pricey, but not prohibitive.[1] Long-distance moves are usually pretty costly anyway.

1. https://pets.costhelper.com/pet-shipping.html

2.5k "not prohibitive". lol alright. I've moved 3 times over seas. Never has is cost anywhere near 2.5k (including when my family moved to the US in 91).

91 was almost 30 years ago. $2.5k today is the cost of an economy round-trip ticket from the US to someplace like India or China around the December holidays.

I think if the only animals in airplane cabins were service animals and pets of people moving long distances, the impact would be extremely small. It wouldn't be an extremely common hassle that essentially every flyer has to deal with.

There are quatantine periods.

Source: I lived there and have friends whose pets had to go through quarantine. You can either do the quarantine on the mainland before travel, or in Hawaii after travel.

If we’re being snarky, ships also move over water you know, and you can ship your animal in a crate and the crew can feed it and clean up after it, regardless of size. People shouldn’t have to put up with your dog peeing/crapping in the cabin on a long transoceanic flight. It can ride in the cargo hold or on a ship just fine.

Lots of pets die in the cargo holds. Nothing but luggage should really be down there.

Where does your dog or cat go to the bathroom on an overseas, international flight?

Ideally? In a litter box.