You can't compare international football domination because one trio belong to the same national team and the other belong to three different ones. The latter can't dominate together, and in the case of Kroos and Modric, one of them winning a major title requires the other one to lose it.
Nonetheless, Toni Kroos and Luka Modric both played in consecutive World Cup finals, with Kroos winning his.
Xavi was not a starter in his last season at Barcelona. They won that league, and then two of the next three. At that point, Iniesta retired. Barcelona then won the league again. They are currently 1 point away from 1st and have a good chance of winning their second league title in three seasons without Iniesta. It would be their fifth league title out of seven since Xavi retired, which is about the rate they had in the seven years before Xavi retired.
That's not to say they don't deserve some credit for being part of league-winning teams. But let's be clear about what we're actually looking at here.