[Simpliplant]

If you replace axe with chainsaw, you can’t expect it will perform better if you keep the same workflow of smashing the thing into the tree. To get the advantages you have to adjust your workflow, otherwise it will of course feel like an obstruction.

[jongjong]

It's not the same because maintainable JavaScript code essentially always converts to maintainable TypeScript code. Adding type annotations to existing JavaScript code won't make it harder to maintain. However, maintainable TypeScript code will not necessarily convert to maintainable JavaScript code after removing the type annotations... Yet as well as TS can hide the tech debt and delay repayment thereof, it's still tech debt and you still have to pay interest on it.

Anti-patterns are the same in JS and TS; tight coupling and low cohesion is bad, complex interfaces are bad, unclear separation of concerns is bad, poor encapsulation is bad.