Right, if you can't do any of those and can only do leetcode you will get hired as a junior. Do you think that juniors need those things? No, of course not, they need to learn that on the job. So juniors gets leetcode. Now, since all juniors can do leetcode, why shouldn't we require seniors to also know it? Otherwise we would hire seniors who are worse than the seniors we grow ourselves. You can say that seems like an arbitrary requirement, but it makes sense, and there is no lack of senior engineers wanting to get hired at FAANG. And getting X years of experience isn't an accomplishment, even the dumbest software engineer will get there after X years.