There are some very legitimate use cases for runtime validation, namely when dealing with external inputs/databases, e.g. https://github.com/gajus/slonik#user-c

There are some very legitimate use cases for runtime validation, namely when dealing with external inputs/databases, e.g. https://github.com/gajus/slonik#user-content-runtime-validation https://github.com/gajus/slonik#user-content-runtime-validat... Flow had [flow-runtime](https://github.com/gajus/flow-runtime https://github.com/gajus/flow-runtime), which was nice. There were/are a few half-baked solutions in TS ecosystem, but nothing as mature as flow-runtime was. However, I wish that TS supported this natively.