As much as I detested the idea of Leetcoding the reason they became the de-facto for hiring was two fold:

- Software development for the most part did not require any particular specialization but it paid really well because of the explosive growth of the internet so there was an oversupply of talent.

- Most companies had no idea what they wanted from hires and how to test them so started copycat-ing puzzle based and algorithm and data science questions from the days when programming was mostly numerical computing

It devolved into a race to the bottom as more and more people lured by the 300k packages lined up and companies well aware of "No Silver Bullet" threw these people at increasingly menial tasks.

Companies at Leetcode and Hackerrank have no relevance now that you can ask an AI agent to do a hyper specialised candidate selection based on the role, with most roles now being redundant every six months.