It's an arms race. Big name employers only wanted the top 1% of candidates. A bunch of people wanted to get into the top 1% and figured out a way (leetcode, ctci, etc.). And then employers kept only wanting the top 1% - so they just raised the bar higher and higher.
Now we're at the scale where if you haven't done a minimum of 200 problems before any interview round - you're not likely getting an offer from FAANG/etc.
Now we're at the scale where if you haven't done a minimum of 200 problems before any interview round - you're not likely getting an offer from FAANG/etc.