Typescript compiler is first and foremost a type system for Javascript. It's not an independent language. In fact it broke backward compatibility many times to follow the ES spec.

> One should also understand the machine code that a traditional language compiles to and how the CPU executes it. Ultimately, your language compiles to machine code. /s

If libraries you use are all written in machine code, then sure, you should have an understanding of machine code. Your comparison clearly doesn't work here.

> No one should need or worry about what an abstraction compiles to unless they’re specifically working on that abstraction or there’s a language bug.

When an abstraction is that leaky, it's barely an abstraction. Typescript does force you to choose a Javascript version as a compilation target. Obviously you are forced to know what Javascript version supports what feature because Typescript isn't going to polyfill every missing feature depending on your Ecmascript target.