The pitch deck version of digital health goes something like this: AI replaces the clinician , costs drop, access expands, outcomes improve, everyone wins. The pitch has been effective. Venture capital has poured billions into companies built around the premise that removing humans from the care loop is both possible and desirable. The premise has a problem, and the problem has a number. Ruben Sandoval Davila, C o-founder and CTO Avena Health Two percent. That is the share of active users remaining after three months on a clinical nutrition platform that, according to its own internal data, had previously retained 40% of patients for eleven months or longer. The platform is Avena Health . The person who built the automation, watched it fail, and then rebuilt the architecture around the failure is Ruben Sandoval Davila, the company’s co-founder and CTO.…