Daniel D'Addario Chief TV CriticAmerica is no longer leading on the world stage in one crucial metric.We’ve lost game-show-host supremacy.On “Jeopardy!,” the standard-bearer for American quiz shows, star power has been outsourced to the contestants. And recent long-running champions Amy Schneider and Matt Amodio lent energy that had otherwise been missing. The recent endless cycling through “Jeopardy!” guest hosts having ended in a fiasco and then a compromise has left Ken Jennings and Mayim Bialik, dividing the role, adrift.