Credibility is not the same as authority.
Of course Pius V or Pius X is more credible than Bergoglio.
But neither Pius V or Pius X had more juridical power than Bergoglio, and neither one had the power to tie the hands of any future Pope in the exercise of his juridical power.
This does not mean that I think the Missal of 1969 was not a disaster, etc.
AM is correct about changes to the missal AFAIK. My agreement with you RAB is that, as you say, the issues go back to VII. Anyone who thinks that this “civil war” is only Francis’ doing is sorely mistaken.