We must admit that the Catholic Church today is the same organization with unbroken continuity with that organization (Church) started in the 1st century. A reading of the Apostolic Fathers, the hinge figures between the Apostles and the later 1st and 2nd century, makes that clear.
The question is whether at some point the one visible, holy, Catholic and apostolic Church lost its legitimacy, thereby releasing the faithful to leave and start rival churches and communities.
Of course, if Jesus started the Catholic Church, we (and He) would expect it to continue until His 2nd Coming at the end of time. If it fails to the point of illegitimacy then His promise that the gates of hell would not prevail against it was a lie or He was not competent enough to keep His promise.
I think the conclusion should be obvious. Protests against Jesus’ Church are not legitimate, nor are churches set up to rival it.
Is the Church perfect? No, because I joined it and I am a member. I know my own sins. Even if the Church was perfect before 1994 when we joined, it certainly wasn’t afterwards. There was never a Golden Age (just read St. Paul’s 1st Letter to the Corinthians). The Church is always reforming and always in need of reform because it is full of people like me. It is not only a haven for saints but also a hospital for sinners
Jesus said He would build His Church — not “churches.” Jesus prayed that His followers would be perfected in [visible] unity which is now quite visibly gone (except in the still unified universal Catholic Church). The Catholic Church has never lost its legitimacy and the faithful are not released to start rival communities or to join them. This was Luther’s great sin of schism.
“Throughout history, many splinter groups claimed the name “Church”, but as Cyril of Jerusalem said in 350, ‘And if ever you are visiting in cities, do not inquire simply where the House of the Lord is,—for the others, the sects of the impious, attempt to call their dens the Houses of the Lord,—nor ask merely where the Church is, but where is the Catholic Church. For this is the name peculiar to this holy Church, the Mother of us all, which is the Spouse of our Lord Jesus Christ, the only-begotten Son of God’.(Catechetical Lectures 18, 26, in Jurgens, Faith of the Early Fathers, 1:359).” (Crossing the Tiber, pg. 70).
Bottom line: it is NEVER OK to break with the Catholic Church that Jesus founded 2000 years ago.