[kristiandupont]

You might like TS Reset: https://github.com/total-typescript/ts-reset, which fixes this particular problem. I don't personally find it to be a big issue though.

Regarding runtime type checking, if you were to write something that can handle the total space of possible TS types, you would end up with incredibly complex machinery. It would be hard to make it perform, both in terms of speed and bundle size, and it would be hard to predict. I think Zod or perhaps https://arktype.io/ which target a reasonable subset are the only way to go.