The difficult with backend is dealing with state. It's easy enough to provide a simple experience when dealing with stateless frontends, backends are a very different story.
You're right that we need better tools. I'm the founder of Encore [1] which is all about bringing the simplicity of Vercel/Netlify to backend development. Not by substituting the backend for a BaaS but by building a developer experience hand-crafted for dealing with cloud infrastructure.