Maybe he should step into a Catholic church. One faith. Multiple ethnicities. That was one of the benefits of the use of Latin. You could go into any church in the world and have the same Mass. No balkanization.
Yeah, I can see the advantage. Every church service in Latin where less that 5% understand vs the local language where all but 5% understand. Much better.
What is the lesson of Pentecost to you when the apostles spoke to the crowd in their respective languages?