I think it was necessary, but the reason why it didn't work so well is because it did not address the issues of the day head on. There were no dogmas clarified. Communism was not addressed. They played around, and dissapointing results were what they got.
I suppose the Council could have been more relevant if it had concrete in its answers and documents. It could have addressed many of the ills of the day. As to liturgy, vernacular only would have made a big difference to the youth I guess. But this vague "spirit of Vatican 2" open a huge window that let in a foul breeze.
What was the process at other coucils? Was it different?..didnt group think apply in those like Nicea?
It would take a massive combination of many of those. A huge purging.