I’m not sure what you think you know about Catholics but we do read the Bible. Often. And when we speak of Revelations we know that the writing is divinely inspired to be true for the times it was written and true for all times.
The seven Churches, a blessed number, is also interpreted to be about the seven continents, meaning the whole world that has finally heard the Gospel. It’s the fulfillment of the mandate Christ gave the Apostles to spread the word to all men. A Church instituted by Christ, prayed for by Christ himself, would never be corrupt. The flawed humans, from Peter and Thomas to today, are always with us. But the teachings Christ gave us are intact and we still abide by them.
We agree about Luther.
I find it amazing that very plain words can be 'interpreted' so many different ways!