You do realize that you're moving part of the cognitive load until later and increasing it when you have to implement a type checker in unit tests for every program you write.
And if you're really good, you'll use that full power to develop a toolset of useful ways to verify that certain properties about your code hold! You'll see common errors and write infrastructure to help your unit tests ensure those errors aren't happening. You might even add annotations into your code as you write it to automatically write those unit tests for you. And you will have invented ... the Inner Type System!
