There is no other proposition in economics that has more solid empirical evidence supporting it than the Efficient Market Hypothesis... In the literature of finance, accounting, and the economics of uncertainty, the EMH is accepted as a fact of life.
It is difficult to systematically beat the market. But it is not difficult to systematically throw money down a rat hole by generating commissions and other costs.
Very little evidence was found that any individual fund was able to do significantly better than that which we expected from mere random chance.