I'm curious, what do you want to test? The classic "memorize how to bubblesort" interview questions which so many people complain about because they don't show

I'm curious, what do you want to test? The classic "memorize how to bubblesort" interview questions which so many people complain about because they don't show anything except that someone has prepared? Isn't it better to just look over the code of applicants and check if they are aware of general structures etc? Obviously some familiarity with algorithms etc is required and it should be checked if that's there, but with tests you can't really test if someone understands the bigger picture and did not just memorize the answer. I know more than enough people who can solve problems just fine but their code is absolutely atrocious and I'd never hire them. Interviews where one can ask them why they write code the way they do are probably far more effective.