Access to coaches and coach training in America is dramatically higher than in a lot countries. Access to gyms is higher. Look how saturated the markets are. People frequently chose to drive hours to a certain gym, but the vast majority of participants have a gym very close to them.
Travel within America is cheap. I know people there think it isn’t, but it is. For us, to travel to a competition where our senior 2 had more than 1 team to compete against is a minimum 8 hour drive, to compete to qualify for a Worlds bid is the same distance. A flight from where I am to nationals is almost $700. Then there’s an 90 minute drive. Which is exactly why we don’t go, because the trip for the weekend costs close to $2500.
America views cheer generally as a sport and it receives support from schools and gyms.
Other places aren’t so lucky because they’re behind because cheer is so new.