An accurate test would just be handing them a real piece of work to complete. Which would take ages and people would absolutely hate it. The interview questions are significantly faster, but easy to cheat on in online interviews.

The better option is to just ask the questions in person to prevent cheating.

This isn’t a new problem either. There is a reason certifications and universities don’t allow cheating in tests either. Because being able to copy paste an answer doesn’t demonstrate that you learned anything.