As did the Coptic and the Syriac. Why? Because of doctrinal differences. No different than the Protestants. By your logic then all the other branches of the Catholic church are heretics.
The problem with you and other members of the RCC is your continued arrogant heresy that you are the one ‘true Church’ and that all the others need to bow to your Supremacy. What I see is one arrogant and contentious division attempting with great pride to assert itself over the other branches of Christianity.
What I will counter is that the members of the RRC need to humble themselves, knock off the bravado and swagger, accept their place and role, and minister to their flock, and quit trying to jockey for position and usurp leadership that doesn’t belong to them. Learn to stop trying to be the greatest, and start learning to be the least.
Popes in the past have condemned them ex catherdra.
Catholics who accept them are then technically, not in agreement with their own infallible pronouncements of their own church.
That puts them in a very precarious position, according to their own Catholics church which condemns anything but lockstep agreement with it.
Schismatics are those such as EO.
This shows the hypocrisy of the Catholic church.
Pope Boniface VIII, Bull Unam sanctam (1302): "We are compelled in virtue of our faith to believe and maintain that there is only one holy Catholic Church, and that one is apostolic. This we firmly believe and profess without qualification. Outside this Church there is no salvation and no remission of sins, the Spouse in the Canticle proclaiming: 'One is my dove, my perfect one. One is she of her mother, the chosen of her that bore her' (Canticle of Canticles 6:8); which represents the one mystical body whose head is Christ, of Christ indeed, as God. And in this, 'one Lord, one faith, one baptism' (Ephesians 4:5). Certainly Noah had one ark at the time of the flood, prefiguring one Church which perfect to one cubit having one ruler and guide, namely Noah, outside of which we read all living things were destroyed… We declare, say, define, and pronounce that it is absolutely necessary for the salvation of every human creature to be subject to the Roman Pontiff."
— Pope Boniface VIII, Unam Sanctam (Promulgated November 18, 1302) "If, therefore, the Greeks or others say that they are not committed to Peter and to his successors, they necessarily say that they are not of the sheep of Christ, since the Lord says that there is only one fold and one shepherd (Jn.10:16). Whoever, therefore, resists this authority, resists the command of God Himself. " http://www.fordham.edu/halsall/source/b8-unam.html
Pope Boniface VIII, Unam Sanctam: “We declare, say, define, and pronounce [ex cathedra] that it is absolutely necessary for the salvation of every human creature to be subject to the Roman Pontiff.” "If, therefore, the Greeks or others say that they are not committed to Peter and to his successors, they necessarily say that they are not of the sheep of Christ, since the Lord says that there is only one fold and one shepherd (Jn.10:16). Whoever, therefore, resists this authority, resists the command of God Himself. " — Pope Boniface VIII, Unam Sanctam (Promulgated November 18, 1302)
http://www.fordham.edu/halsall/source/b8-unam.html
Pope Eugene IV, Cantate Domino (1441): "The most Holy Roman Church firmly believes, professes and preaches that none of those existing outside the Catholic Church, not only pagans, but also Jews and heretics and schismatics, can have a share in life eternal; but that they will go into the "eternal fire which was prepared for the devil and his angels" (Matthew 25:41), unless before death they are joined with Her; and that so important is the unity of this ecclesiastical body that only those remaining within this unity can profit by the sacraments of the Church unto salvation, and they alone can receive an eternal recompense for their fasts, their almsgivings, their other works of Christian piety and the duties of a Christian soldier. No one, let his almsgiving be as great as it may, no one, even if he pour out his blood for the Name of Christ, can be saved, unless he remain within the bosom and the unity of the Catholic Church."
Pope Eugene IV and the Council of Florence: "The sacrosanct Roman Church...firmly believes, professes, and proclaims that..not only pagans, but also Jews and heretics and schismatics cannot become participants in eternal life but will depart `into everlasting fire...unless before the end of life the same have been added to the flock; and that..no one, whatever almsgiving he has practiced, even if he has shed blood for the name of Christ, can be saved, unless he has remained in the bosom and unity of the Catholic Church.”— Pope Eugene IV and the Council of Florence (Seventeenth Ecumenical Council), Cantate Domino, Bull promulgated on February 4, 1441 (Florentine style), [considered infallible by some]