[spamizbad]

Mainly it's just annoying if you've been working for 4+ years and haven't touched that stuff in a while. It's an entirely separate skillset separate from your role as a developer. The fact that there have now been several studies showing it doesn't correlate with job performance makes its emphasis in interviews questionable.

There's also some fear on the "poseur" factor that people worry about. If candidates can simply rote-learn their way into senior roles I wouldn't really feel comfortable having them as team members.

With that said, I do like think the advice of reading Programming Pearls and Designing Data-Intensive Applications -- two books useful for the job at hand, and just your general knowledge of how systems work and how to approach problems. Leetcode, by contrast, is empty calories.