Notarization is another great example of "the real world is strange to technical folks." There are a thousand reasons that notarization is a terrible process. There are minimal requirements to be a notary. Notaries have predictable seals. Ordering a fake notary stamp is pretty easy. There's no technical deterrent to backdating requests. Notaries are frequently employed by the people they're notarizing for. Notaries are not trained to recognize fake IDs.

Even the flimsiest of technological improvements could radically improve the trustworthiness of the notarizations, but by and large the system works, so there's not much of a reason to fix it yet.