In February 2026, the US software sector suffered a historic sell-off—Adobe down 62%, Figma down 86%, ServiceNow down 59%. The trigger wasn't earnings misses but fears over GenUI (Generative UI), a paradigm shift where AI generates interfaces directly. This article uses three case studies and a four-dimension moat framework (switching cost, data moat, AI readiness, capital firepower) to evaluate which software companies can survive the AI era. Includes a six-month risk map and three scenario analyses.