Your post makes it seem like only two large track stadiums exist in the world. There are a ton of large enough stadiums around the world that can seat 15k-30k spectators, and obviously way more people would be watching on TV or online streams which is where the real money comes from. The olymipcs costs a lot of money because they build new facilities for a ton of different sports all in the same area, and new housing for a ton of athletes. If we're talking track and field only, the stadiums already exist in a lot of countries and cities. Places that can already get it done in just the US are Oregon, California State University, Arkansas, Texas, Drake, Penn, New York, Jacksonville, Kansas, multiple options in LA area, Stanford is capable if they bring in the extra bleachers, the list goes on. Most of these places are near colleges where dorms could be used, or lots of hotels. New athlete villages are not necessary. Tons of places in other countries as well like every location of diamond league meets, plus old Olympic stadiums.