The federal government doesn't manage any national credit agencies.

I don't see how that matters, the point is that we don't need the federal government's mandate in order to have a national clearinghouse of title data.

Since title events, like marriages, can happen outside the US, that only helps a little.

That’s not what’s being discussed. In other countries that operate under what’s called the Torrens title system, the government maintains an authoritative central land registry. If you wind up in a legal dispute about ownership of a piece of land, the judge looks at the government books and is bound by what they say (with minimal exceptions).

We cannot have such a national registry in the United States. We could have 50 independent ones, but the few states that tried it have given up and reverted.