That's an idealistic way of looking at things.

People would look-up solutions to that exact problem; it's very hard to come up with a unique problem that was never asked before, and questions leak pretty quickly. (especially at larger companies)

The goal of a test is to evaluate whether you'd be a good employee; I agree algorithmic questions are not representative of day-to-day work, but evaluating your friend's ability to help you is out of scope. Companies want to hire someone that has decent programming skills; you can't rely on other people to solve all your problems, you need to have a minimum level of skill.

[again, playing devil's advocate here; we all agree the process is suboptimal, but let's not ignore the negatives of some of the alternatives suggested here]