Is there a National Graves Registry? Should there be?

Any military person buried in a Federal / National cemetery is on a list somewhere – link

Is there a similar finding aid that compiles grave information on a national scale for city cemeteries, church cemeteries, and privately owned cemeteries?

Would that be a useful service?

Sometimes I think that compiling a list of people from their headstones, and copying the epitaphs / engraving – would be an interesting hobby.