You probably don't have any Mormon's in your country. And where we live Mormons are a very small number. The only place they are the majority is Utah. So they control an entire state. They are nice people. You have to understand Christian sects in America are all working a different angle. The born agains say the Catholics are doing it all wrong. Catholics are baptized as children. You have to be baptized as an adult. It's not enough to just be baptized as a child. But most Catholics and my own Greek Orthodox, only baptize as babies. So Born Again's say we are going to hell. I love it! They have a great angle to steal away people who were once Catholics.What you call "dark age" is the birth of our current world. Do you say to a pregnant woman "You pregnacy is a dark age?". In the so middles ages for example 1/3 of a year had been holy days without work. Some people travelled thousands of miles on a pilgrimage for two or more years. And to take a bath together with the own lover in a common barrel was also a nice thing. ... and so on ...
The Catholic church lost what?
I guess you speak about a time when the nobles of the city of Rome elected the Pope - which is by the way in gerneral the oldest active election of the world. And why I am sure now that you now in the moment knownot any concrete pope in his time of history and what really had happened there. You live in an abstract world where everything is simple and easy - except your own life and the life of ... ?
You will perhaps not be able to see this - but it is really sometimes amusing and also astonishing for members of foreign cultures to have to see that US-Americans normally try to reduce everything to a story of rivalry. Mormons vs Catholics is not a theme for Catholics. We are the church of the children of god. If a Mormon needs help she/he is also able to ask Catholics to help her/him. And this is not a question of a price like to have to become a Catholic. On the other side we will normally not hurt our own values. So our answers will always be open (=not predefined) in a concrete context of the future which we will have to understand first.
The Catholics have nothing to offer. No one is joining the Catholic Church. You are only born into that church. Or marry a Catholic. Most people who are born into it leave to be Born agains.
I'm not saying I believe Mormons I'm just saying they have a very good story. The Jesus story 2020 years ago they say is all true. It all happened. And the first pope was Peter. Who was the second pope? 3rd? 4th? The stories get worse and worse. So the church has lost it's moral authority that they once had with God. Peter was a good pope. Maybe the 2nd one was good. Maybe the 10th. But then suddenly they got evil/immoral/corrupt/gay. Today the Vatican is a gay brothel.