A lot of software developers are asked to code solutions to difficult problems using nothing other than a whiteboard. Given that under normal circumstances we use a computer, IDE, and the internet, I can see why some might opt to use spaced repetition to ensure employment.
If the interviewers aren't generous in offering corrections to small issues when you're at the whiteboard, you don't want to work for them. Whiteboard exercises are there to see how you think through a problem, not how much algo shit you crammed ahead of time.
You still often have to be familiar with approaches to problem solving and data structures. And you have to be practiced enough to know when to apply them.
In a high pressure situation like an interview, I personally find it difficult to think naturally through a problem. Familiarizing myself with different types of interview questions regularly helps a lot.