A service which is intended for the general populus ought to be understood by them. Here in the US Muslims will have sermons in English… and even might have extra shifts in the Somali language for a large population of Somalians who aren’t fluent in English. The purpose is for them to understand the message being preached to them.
The Qur’an has been translated for meaning, so anyone should be able to grasp at understanding it.
But recitation of it, and the prayers–that is in Arabic. A universal language, of sorts. A person can pray the same prayer anywhere in the world, and don’t need to be fluent in Arabic, just only need to learn what’s in the prayers, which is pretty simply. The Qur’an uses less than 2% of the Arabic vocabulary so it is also relatively easy to learn, although there are translations which most people use to understand instead.
If someone is going to come to mass, it might be they have to learn Latin just to understand. And in fact, that doesn’t bode well for universality.
Jews at least have scripture that was revealed in Hebrew, a good reason to maintain the study and use of Hebrew in services. The same for Muslims and Arabic.
Christians don’t have that, though… so it seems strange and artificial to me to adhere to the Latin as if it’s somehow holier or better than another language… when that’s not quite backed up in its historical traditions.