I think that is a reason the catholic Church still uses it for things like papal encyclicals. It puts different groups on a more equal footing.
Far more people understand it than things like Esperanto. Quite a lot of people know it a bit. I did it at school. My kids learned some (their choice to do it up to GCSE level).
That said, in practice, English is the international language. It is what is most likely to be used at an international conference in most fields, or when people with two different native languages speak.
English is the international language now. About a century ago, the lingua franca of the technological world was German. Half of my father's university text books were in German, pretty much all of mine were in English. Things can (and do) change.
Except now the whole world is in a common meme pool. Thanks to the internet, Metcalfe’s Law applies to languages globally. China may stave it off for a while by firewalling its population... but the rest of the world won't care.
It's not going to change again. Not even if the US and UK both sank into the ocean.
> that is a reason the catholic Church still uses it for things like papal encyclicals.
Nah, it's just because that particular institution tries very hard to be internally consistent, for historical reasons. They immediately publish translations of such documents into "common" languages as well, and that's what non-clerics will actually read.
I said a reason, not the reason. Both can be true.
English is a living language so it's a bad choice (at least from my criteria ;) )
Yes, agreed. That was intended to be a BTW and Latin is probably the best choice on your criteria.