AI threatens B2B SaaS by enabling customers to build solutions with vibe coding, reducing reliance on traditional software. This shift has led to declining SaaS stock prices and increased churn as customers demand flexibility. B2B SaaS must adapt by becoming integrated systems of record, ensuring security, and allowing customization. Companies that evolve and enable user-built solutions will thrive, while those resistant to change may fail. The future hinges on offering platforms for customer innovation rather than fixed products.