To hop on a plane and AirBnB, you also have to, you know, book a ticket and a room. The level planning required is similar in scope to that, it's just unfamiliar to those of us privileged enough to live in countries that are largely permit visa-less travel. To the rest of the world, getting a visa is every bit a central to foreign travelling as booking a flight.
(.. leading to situations such as once when ... my friend ... had to cancel a trip to India last minute because he hadn't thought to apply for a visa.)