Arguments about VII are circular and thus, defective reasoning. They go something like this:
1. Vatican II is pastoral. It contained no infallible declarations.
2. But as part of the magisterium of the Church, it requires our assent.
3. So what did it teach that is different from the past?
4 Ecumenism, freedom of conscience, collegiality and subsidiarity "…Nevertheless, many elements of sanctification and of truth are found outside its [the Church’s] visible confines".
5 Do these things help our sanctification, individually or collectively? Do they require our faithful assent?
6. No doctrines were proclaimed at Vat II.
But Vat II is a very good cover story for the real project; the denial of one or more doctrines of the Church: The Real Presence, the nature of Priesthood, the sinfulness of contraception and divorce, damanation, Judgement, the seriousness of Mortal Sin.
"Vatican II said …" = "What I think the Church should say, but doesn’t".
This is simple Protestantism come ’round again: We simply can’t bear the hard sayings of Jesus and the work they make for us. So we make things easier for ourselves.
Then add the new mass and later populist modifications.
Result: What you see in Catholic schools and churches today.
Modern Catholicism contains contradictions: Holiness through populism, sacrality through mundanity, progression through archeologism, change as part of Tradition. This leads, in those orders and dioceses who espouse these ideas, to an implosion; they are consumed by ennervation; the contradictions sap their energy.
We can see the future of Modern Catholicism in Protestant sects today.