My own mother could have benefited from an alternate means of establishing citizenship. She was born in Arkansas, to parents who were both native-born US citizens.

There were a lot of "irregularities" concerning my mother's birth certificate. I won't bore you with the details, but suffice to say that getting a passport was difficult for her, made easier because her own mother was still alive and could swear an affadavit to amend her birth certificate.

I know of other people, mostly elderly now, who never got birth certificates. They were born in the US and are fully legal citizens, but never had a need for a real birth certificate, until now.