This is pretty much obvious for people migrated from JavaScript to TypeScript and suddenly realised that most of their unit tests can now go to a trash bin.
I’m speaking from a Python background. I love types and use them religiously, but I had no idea how much better (modulo runtime checks; that one’s obvious) others were at it.
It's been 8 years and I can't imagine ever writing untyped JavaScript again. Garbage garbage garbage.
If you're on TS and want end-to-end type safety, I recommend you validate everything with something like Superschema and Zapatos/PgTyped. Node with 100% type safety is wonderful to work with.
