There has to be an office, and at least two of them (such as the monarch and his subjects, two offices).  That's what makes marriage and family—and the Church—an not only institution and tradition, but organization.
		
		
	 
Marriage is an institution, and a tradition, from antiquity, but marriage is also an organization, a very simple one, the most simple organization, just two offices, filled by just two people (Jesus outlawed polygamy formally); a two-member organization.
	
		
	
	
		
		
			We don't need Peter to be the first pope to establish Catholicism.  We only need the office of Bishop, 1st Timothy 3:1, which has existed since the first century, before the Jewish temple was demolished and rabbinical Judaism was established.  The Apostles were the original, founding guardians, custodians and stewards of the office of Bishop, and now we call their successors in that endeavor, the Bishops themselves.
		
		
	 
You could argue that the guardians, custodians, and stewards of the office of Bishop, are Catholic families, and lay.  If you wanted to argue that I'm wrong.  "No, the Bishops can't be their own guardians, custodians, and stewards.  Some other party must fill this role.  Just grammatically."  You could say.
Bishops are basically local boys.  In Boston, we just got a new Bishop, he came from Rhode Island.  He succeeds another local boy, Cardinal Sean O'Malley (Boston Irish Catholic).  So, we ultimately possess the absolute power to keep all of our boys away from that office.  We could suffocate it, nothing hinders (nihil obstat) us from doing that, as a collective.  The Pope, and no Bishop either, couldn't stop us, if we wanted the Bishop of Boston to be a vacant seat (sedevacante), we could snuff it out like a candle.  No Catholic boys means no candidates for Bishop.
We're not doing that—but we could do that.  Nothing hinders (nihil obstat).  Stands to reason.  Self-evident.  Lay Catholic families possess (are the guardians, custodians and stewards of) their local office of Bishop.