Leetcode is simply testing whether you studied Computer Science, took Data Structures & Algorithms course, and read the CLR book on algos and practices it. Nothing else. This is really freshman level cs work. very simple.

people who cannot leetcode - a simple data structures & algorithms inteview - cannot understand runtime nuances of what they write.

This is how you end up with N+1 algorithms and exponential runtime.

For example look at all modern front-end in javascript - usually leetcode is more relaxed for front end, and you end up with ungodly gobbles of unnecessary loops inside loops wrapped in loops that traverse DOM for no good reason and freeze the browser.

it is the javascript people who import node libraries that contain 3 lines of code, instead of writing it properly