Congrats to the Americans on winning the World Christian Championship!
Only in the Latin Orthodox division.
Most Christians are Catholics.
Most Christians are not Catholics, though it's close and recently was true.
https://en.wikipedia.org/wiki/Christian_denomination says just less than half of Christians in 2024 were Catholic (48.6%), down from 50.1% in 2011.
He no doubt means the largest Christian church (though from a Catholic perspective, there is only the Church and those who are in schism, heretics, etc.).