Well, I don’t have the time or interest in entering a full argument about this. Basically, the SSPX argued that Vatican II was heretical, and that the Pope was the Antichrist. Also, that theirs was the true Church and the Catholic Church went off the rails. And so forth.
That is very different from thinking that there were problems with Vatican II. Also, that Vatican II was taken by liberal Catholics, including many priests and bishops, and used to do things that it really didn’t call for. The so-called “Spirit of Vatican II.”
I have read all the documents of Vatican II, and am persuaded that there are no actual heresies in any of them. that accords with the teaching of the Church that the Holy Spirit will watch over it and prevent the Pope, ex cathedra, and formal councils from any heresies. A couple of times Popes have come close, but they have backed away from formal heretical pronouncements. Some Popes have been bad men—the Medicis spring to mind—but even they have not formally promulgated heresies.
On the other hand, not every council is especially useful. Nicea and Trent were vitally important. Some others have pretty much been forgotten, and accomplished little. My own feeling, FWIW, is that Vatican II was one of those. Better if they hadn’t held it, probably, although it’s still too early to tell for sure. Many of the problems were already infesting the Church, and Vatican II was merely an excuse to bring them out.
In any case, SSPX like the Anglicans was given a lot of latitude to do their thing, provided that they consented to recognize the authority of the Church. And it seems that they are refusing to do that.
“and that the Pope was the Antichrist.”
I stopped right there. Until you provide evidence of the above, I will assume you are not a truthful poster.