I’ve been to a Catholic church and I’ve sat through your mass.
Its not a lie and its not false testimony
You see, you don't get to decide the intentions of other people. You just don't have that kind of power. You can easily say you believe that's what they're doing, though you'd be wrong.
But worship of idols is a question of intent, and if that is not their intent, you can't change that. You have no effect on it.
Furthermore, the Catholic Church does not teach idol worship. You might interpret that way--go right ahead if you want--but you'd be wrong and your interpretation does not affect what is actually being taught.
Your judgmental false testimony slanders about a billion people. Why do you seem so sanguine about that?