That is completely false.
It is not false. What it is, is that you have convinced yourself that it is false in order to maintain your dogmatic sedeism.
It's quite the conundrum you have going on.
On the one hand, you know that we need true, holy popes to teach the truths of our holy religion, on the other hand, you turn around and reject what true popes teach. Quite the conundrum you've created for yourself.