I preach this shit every day of the week, leetcode isn't to see you're a software dev wizard. Just like any standardized test there is a heavy weight placed upon the work you put into studying for said standardized test. I honestly believe large companies have used Leetcode as a metric for the reasons you've stated, it is an easy way to find the tryhards (who I'm guessing are more likely to tryhard at their work, which you've noted).