You just said that you see no difference between people that take leetcode and those who don't So why the hell use leetcode as a filter if it doesn't filter for anything?
Filtering for people willing (and able) to Leetcode is the point! When you have a large talent pool, you will have to come up with a filter; and there is also an element of luck involved - but I don't think interviewers or interviewees will be happy for an offer to be hang on a coin-toss.