I think you have a misunderstanding. Most companies that do LC-style interviews usually show unknown problems.

Memorizing the Top 100 list from Leetcode only works for a few companies (notably and perplexingly, Meta) but doesn't for the vast majority.

Also, just solving the problem isn't enough to perform well on the interview. Getting the optimal solution is just the table stakes. There's communication, tradeoffs between alternative solutions, coding style, follow-up questions, opportunities to show off language trivia etc.

Memorizing problems is wholly not the point of Leetcode grinding at all.

In terms of memorizing "patterns", in mathematics and computer science all new discovery is just a recombination of what was already known. There's virtually no information coming from outside the system like in, say, biology or physics. The whole field is just memorized patterns being recombined in different ways to solve different problems.

It’s not about memorizing individual problems per se, but rather recognizing overall patterns and turning the process into a gameable endeavor. This can give candidates an edge, but it doesn’t necessarily demonstrate higher-level ability beyond surface familiarity with common patterns and the expectations around them. I’d understand the value if the job actually involved work similar to what's reflected in leetCode style problems, but in most cases, that couldn’t be further from reality. leetCode serves little purpose beyond measuring a candidate’s willingness to invest time and effort. That’s the only real virtue it rewards. But ultimately, I believe leetCode style interviews are measuring the wrong metric.