There were many attempts at that, JetBrains MPS (metaprogramming studio) comes to mind, but all them feel clunky and constrained. Many proprietary programming

There were many attempts at that, JetBrains MPS (metaprogramming studio) comes to mind, but all them feel clunky and constrained. Many proprietary programming systems do follow this model, like Mathematica and visual IDEs like PLC programmers. But to bring it to wide programming audience we need to agree on an open format for representing syntax trees and implement several editors for typical use cases, from ultra-lightweight slow-connection-SSH-capable to more or less fully featured IDEs. Though I don't know much details about them, tree-sitter and language server protocol could be centers of crystallization for such software. I hope we'll see interesting developments in this space.