One problem is that the big companies (that, for the most part, pay the big bucks and people care about and other small companies look to) are market movers. If

One problem is that the big companies (that, for the most part, pay the big bucks and people care about and other small companies look to) are market movers. If they are known to be doing some alternative to leetcode then leetcode-type websites and study programs will pop right up to optimize for whatever new metric they have. If they start to prioritize things you've built over ability to perform, you can bet your bottom dollar that within a week there will be a million guides on crafting the optimal cookiecutter project to get in the door at Facebook available on the web. And the signal will lose its value. A signal has to be costly to acquire and algorithmic prowess, although made easier through things like leetcode, is costly for everyone to acquire which is why it holds its value.