It is an historical fact, Emperor Constantine founded the Roman Catholic Church.
It is not a historical fact that Constantine founded any Christian church. It is an ahistorical lie that is easily refuted by the record we have. The Christian church has a history, and there are volumes of Christian writings that precede the time of Constantine and the Council of Nicea. And the records we have of the Council of Nicea refer to that history and show Constantine as gathering the preexisting Christian bishops to hash out a doctrinal controversy. You can’t have a doctrinal controversy without having a preexisting doctrine and church.
You have been spewing a lot of nonsense on this thread without addressing, for example the writings of the Apostolic Fathers dating from the late first century and very early second which are already seen quoting most of the New Testament books. There are hundreds of pages of this material, let alone the thousands of pages by Christian writers in the following two centuries which quote the books of the Bible even more frequently and extensively as they attempt to understand and apply the Biblical doctrine to their lives and the lives of the people who heard them and read their writings. For a little light reading, try the public domain English Translation of the Ante-Nicean Fathers by Shaff.
We also have fragments of books of the New Testament, specifically the gospel of John, dated as early as 125 to 150 AD. There are also multiple artifacts during this time period of Christian art and worship places, as well as a number of non-Christian references to Christ and Christians during this time.
Your assertion that none of this actually existed despite the evidence for it is absurd and if actually made in good faith, shows an abysmal ignorance of the historical record we have.
Constantine didn’t “found the Catholic church”
You have the writings of Clement of Rome - the 4th Pope acknowledged from the late 90 AD.
you have the writings of Justin, Tertullian, Origen etc. all talking about the Catholic church.
you have the Didache, written in 55 AD which lists out the sacraments and beliefs as seen in the Catholic and Orthodox (and oriental orthodox) churches
As I proved above, that is historical fiction. The Church beliefs, doctrines and organization existed and was written about centuries before Constantine.