There is always a compile step (JS -> Bytecode -> Machine code). The question is only if it is visible to you or not. They could have made it totally transparent to you by fully support TS including type checking under the hood including support full TS and not this subset of it, but decided not to do so. There is nothing inherently great to have less compile steps if you are not even aware of it. See v8 how many compile and optimizations steps they have - You don't care, because you don't see it. The only problem of TS is, you will always be able to see it because of it being slow.

I think running TS without type checks is almost entirely pointless.

The point is I don't have to deal with the index.js blob that gets produced by running the compile step myself. Worse yet the source maps. It's significantly less steps so pretty helpful I'd say.