Who do you think consistently does well, and what data do you use to support that view?
I don't know. I am not even sure what is the classification you have in mind when you ask this question -- are you talking about what kind of people do well? What kind of investment strategies? Are you talking about US or the whole world? Do you have in mind the last 20 years or the last 200 years?
what does "average" mean to you?
An arithmetic mean. Is this a trick question?
Buffet has famously outperformed the market and index funds by dint of superior rationality
Really? And how do you establish that particular causality?
Buffet has a specific investment approach. It clearly worked for him, it also clearly did not work for many other people who tried it. And if you posit the existence of Buffet's wealth as evidence that "value investing works", I can posit the existence of Soros' wealth as evidence that currency speculation works.
I don't know. I am not even sure what is the classification you have in mind when you ask this question
My interpretation of this comment is that you're not asking an object-level question of me (why I think value investing is better for the modern American individual investor than technical analysis, for example) but the meta question of why I think that some investment strategies are better than other investment strategies. I'm afraid I don't find that question interesting enough to give it a good answer, and I don't think you would find a quick answer...
P/S/A: There are single sentences which can create life-changing amounts of difference.