As much as people are pointing to bribes, I think it is more that no one in Asia or Oceana wants to host an event like the World Cup.
Most of North America is hosting 2026, pulling the continent out of being considered for 2038.
Three continents are hosting 2030 for some reason, with games in Europe, Africa, and South America, so no one from those continents are going to compete in 2034.
So all you have now is Asia or Oceana. China doesn't seem willing to have international tourists running around its country. India doesn't play the game and generally doesn't do much much in terms of international sports. Japan and South Korea already hosted and don't seem eager to host again. They aren't going to let Iran host. If Turkey tried to host, it would be admitting it is an Asian country.
So all you have is a Middle East Kingdom trying to sportswash itself or Australia, and Australia is already getting an Olympics, so why go for both?
There might have been bribes, but I think we are getting to the point where the current World Cup is a logistical nightmare that few places want to deal with.