I have not referred to ANY Protestant denomination as a "sect" and I find it insulting that a member of any denomination that was founded sometime after the early 16th Century would call the Catholic Church a sect.
Go to Rome and see for yourself, the evidence is clearly there. Whether you accept the Papacy or not, whether you accept that Peter was in Rome or not, it is impossible to argue that Christianity came to Rome and the middle of the First Century and has been there ever since.
Have been to Rome. Spent days there. Enjoyed the Vatican and Tivoli gardens.
I find the contentions mentioned exceedingly flawed.