For a fast-moving SaaS MVP, flexibility usually wins, which gives React the edge early on. But the moment your team grows past three or four developers, the lack of structure in MERN can become a liability. If you miss Angular's out-of-the-box tooling but want the modern React ecosystem, it might be worth looking at Next.js with a strict folder structure, or even NestJS on the backend to get that Angular-like architecture.