Disagree with the thousands of hours. The tasks are actually pretty easy and take about maybe 5 hours for any competent coder to brush up on.

But that's the problem. If a few hours of exercise can dramatically change someone's results then it's not an acid test and it speaks poorly to the quality of whatever team the candidate would be joining.

All interviews are two way streets and the problem is everyone knows what kind of results pass through the leet code filter and so if it's a bad process, perhaps your best candidates will decline to proceed or accept.

You want people whose time is more valuable than your money. That's kinda the whole point of employee/employer social arrangements.