> Or got someone else to do it for you.

I assume you're talking about cheating? That's mostly possible for remote interviews, not that easy to pull off.

> I think you underestimate the skill of interviewers. You can learn a lot about a person from one directed conversation, if you want to.

You can definitely learn a lot, but the three qualities you mentioned were:

> interested in the work, willing to learn, and aren't a jerk

If someone wants the job because of $REASONS that differ from these, they can still practice to show these traits during the interview.

You could dig deeper in their portfolio if they have one, but my point is that the 1h interview is not going to bring you much more with respect to these three criteria you mentioned.