Developers are migrating from Next.js to TanStack Start due to frustrations with increasing complexity, constant API changes, and tight coupling with Vercel. TanStack Start offers a simpler, more transparent full-stack React framework built on Vite and Nitro, featuring type-safe routing, server functions, and flexible deployment options. The framework prioritizes developer control and clarity over abstraction, making it feel closer to vanilla React while providing modern SSR capabilities. Early adopters praise its predictable behavior, easier debugging, and smooth developer experience for both side projects and production applications.