From Novus Ordo Watch: 3.12.2019

The Lefebvrists (the Society of St. Pius X) have long considered themselves de facto, the final arbiter of all things Catholic. In effect they believe that the Holy See must submit to the SSPX, rather than the other way around, because the SSPX “stands for Tradition”, so they think, whereas (the Modernist entity they consider to be) the Holy See has gone astray and defected from the Faith. That such an idea runs afoul of Catholic Tradition does not seem to bother them in the least, for they seem either not to care or not to know about what the Catholic Church “has always taught” — to use one of their favorite phrases —about the Papacy and the necessity of being in union with the Roman See as the criterion for Catholic orthodoxy: “Union with the Roman See of Peter…
is always the public criterion of a Catholic…’You are not to be looked upon as holding the true Catholic faith if you
do not teach that the faith of Rome is to be held”(Leo XIII, Satis Cognitum, n. 13)

The problem is that Vatican II changed the Faith. It is no longer the Faith of Leo XIII.
Point [1]: The SSPX accuses Sedevacantists of being “arrogant” and “proud” for “saying that there is no Pope.” But its not
‘Sedevacantists’ who say it:

Pope Paul IV (not Paul VI) Bull: Cum Ex Apostolatus [16 Feb. 1559]:

—Further, if it should appear that any bishop (even one acting as an archbishop, patriarch or primate), or even the Roman Pontiff (whether prior to his promotion to cardinal, or prior to his election as Roman Pontiff), has beforehand deviated from the Catholic faith, or fallen into any heresy, We enact, decree, determine and define:

—Such promotion or election in and of itself, even with the agreement and unanimous consent of all the cardinals, shall be null, legally invalid and void…Those so promoted by that very fact and WITHOUT THE NEED TO MAKE ANY FURTHER DECLARATION, shall be deprived of any dignity, position, honor, title, authority, office and power.” So the question is: Has Bergoglio publicly “deviated from the Catholic faith?” Of course! The list of his manifest heresies is too long to be enumerated here. But the SSPX although considering the man to be a heretic, still maintains that he is the pope. Why? Because they say so—forget about Cum Ex! Point [2] When the SSPX refers to “Tradition” they use the term much in the same way that Luther understood “Scripture alone,” or “Sola Scriptura.” Each individual becomes his own pope in understanding the Bible. So too, when the SSPX talks of “Tradition,” it is they themselves who interpret it—not past Popes or documents of the Church. Where in all of Church doctrine and practice is it theirs to assume this role? It exists nowhere except in their own minds.

Now who are the arrogant ones?