Also, using esbuild to transpile your TS will not actually check the types. It just transforms it back to JS. For typescript, you really need the official library which is slow and bloated.
It is free if your IDE uses the TypeScript language server and gives you errors integrated with your code editor. You don't have to transpile if you don't want to. You can, as you said, just use esbuild to strip away the type information.
> For typescript, you really need the official library which is slow and bloated.
See above. You absolutely don't. And it's not slow or bloated at all. It has incremental builds, which are essentially instantaneous after the initial build.
Indeed it will not check your types, but as stated elsewhere your IDE can do this for you. This is actually beautiful because it allows you to get correctness feedback on your code but your code will never fail to run due to arbitrary type complaints. If you later feel like you want the full correctness of TS, maybe during CI/CD, you can run the slower compiler and get a gatekeeper telling you if you are doing something fishy.