The coding interview comes usually after they vet your resume, any profiles, get you talk to an HR, and potentially check your references.

Even the coding interviews are just a signal against overall performance given a short amount of time. It's only a sample of data, but if you did your interview right you should be able to protect some against bad people getting very lucky. Just like driving a car; bad drivers tend to stay pretty bad, and good drivers tend to stay safe. Even though there's a lot of ways to define what is a good driver, there's clearer ways to define what is a bad driver, and if someone was a bad driver yesterday they are still probably a bad driver.