I say "plain and simple" because IME people tend to overestimate the novelty of problems and underestimate the impact of "memorized" problems for solving new ones. 3 months of studying for an interview, while extremely annoying, is generally speaking a pretty small amount of time needed to cover a field as vast and complex as DS&A. And yet it is more than sufficient for most because there's extremely little novelty in the problems being asked. They want you to solve classic algorithms, but either dont' want to tell you so or (more commonly, IME) don't realize they are asking classic algorithm problems and only think they are asking some novel problem. Even "simple" techniques will be impossible for a person to solve in an interview setting, and yet if they've seen it before the interviewer will think they are a brilliant programmer. Its a memorization game even though it doesn't directly look like one. IMHO.

> It's unlikely you'll see exactly the same question as one you studied.

FB only asks leetcode questions tagged with 'Facebook'. 100%. I know ppl who memorized these questions and got in.

Well that's even stupider than what most companies do, which is already stupid.

There are only so many algorithms and so many patterns.

Recognizing the pattern is the problem solving part of the problem.

I think the argument is that recognizing the algorithm part through the (usually thin) facade is very easy, once you know the (common) DS&A questions well. I.e. there is a lot of challenge in learning the algorithms, and little to no challenge in recognizing it through the problem. Examples where a person knows the underlying DS&A very well but is unable to recognize the nature of the problem would be a great counter argument.

Yes but there is an infinite number of ways to ask the questions.