I’m not quite sure what you are trying to accomplish here. You’re taking a type checker and comparing it to a small subsection of what you get from TypeScript. If you JUST want a type checker…I suppose it’s valid. You’d be doing yourself a disservice to go through that trouble and not get what TypeScript gives you. You also ignore the fact your development pretty much halts while you fix it — you present this a plus…but in the real world, it’s a huge minus. I also find examples where it sounds like you’re a single developer on a project to be kind of meh. Show me what happens when you introduce this in to a project with 15 coders working on an established code base. Halting development to fix your types is a non-starter.