Vatican I may help to explain. When the doctrine of infallibility came about, all terms must be defined. this is very important. We have the same in our State laws. So, Pope is defined. Laws in the church state that in order to produce a new pope, that man must be "Catholic" or he is not to be considered. Church/Christ states that we will know them by their fruits. Outward/manifest actions of heresies are judged.
The lay people do not need a formal meeting to come to this decision, especially when those involved to vote are of the same caliber.
These popes who kiss the Koran, and wear the Jєωιѕн cap, write books that state anyone is saved and etc. are manifest heresies.
We are also protected if any, non-pope tries to made a doctrine, all terms must be defined. I doubt if a non-pope would do such; for to define would bring out their heretical thoughts, give them away. This happened at Vatican II. Ratzinger was asked to define his suggestions and he refused or stated he had no need to. I believe it was Levebrve who said, "if you try to define, you will give yourself away as heretics."
So, I think the answer to a lot of questions, is the time it takes to read docuмents of the church, and not out of context.
Chapter 12 of Daniel will happen. There will be an end to the continual sacrifice, the Mass. We are very close. No Mass, no clergy? Or no valid clergy? Hm? But it will happen.