Even when they don't have such a ledger, it's not clear that blockchains do much to solve that problem either. The hard part is not the ledger, but the agreement on who owns what, with detailed surveys that are agreed to demarcate "ownership" and therefore enforced by law.

For example: Greece is still in the process of trying to centrally account for ownership of land [1]. There are certain regions where that was accomplished many years ago (e.g. some of the former Italian possessions in the Ionian, where the Italian-era surveys were accepted by the modern Greek state). But in many regions, property boundaries are still informally demarcated and based on oral tradition, which not everyone agrees on. The difficult part is that aspect of it: agreeing on who owns what, and precisely where the boundaries are. Once everyone agrees on the results of surveys and demarcations, actually tracking the result in a ledger is comparatively easy, as evidenced by the fact that nobody has trouble retrieving 19th-century Italian property ledgers.

[1] https://int.ert.gr/greek-land-cadastre-will-be-complete-by-f...