I don't know, but if I could guess, it's because the players aren't just from the US.
Extra innings
It was simply called the NFL Championship. The term Super Bowl was created for the NFL AFL merger in 1967.
It has often been called 'America's Pastime'.
The championship of baseball is called the World Series. Since 1903, the winners of the National League and American League play each other in the championship to determine who is the best team in the league.
Its called Rossin.
It is called the DIVAS CHAMPIONSHIP.
Helms Championship 1933.
It is called a reactant. While catalysts participate in reaction dynamics, they are not permanently changed in the process.
American League Championship Series. The two teams that win the first round of the American League playoffs, called the ALDS or American League Divisional Series, play in the ALCS and the winner of that series goes to play in the World Series.
Derby or the Rams as they are called are in the championship league.
It could be "NFC" championship, or it could be the "Superbowl" depending on your meaning.
Those who participate in a race are called racers.