"Market efficiency implies that if a problem is valuable and solvable, it’s overwhelmingly likely that it already would have been solved." I think it depends o

"Market efficiency implies that if a problem is valuable and solvable, it’s overwhelmingly likely that it already would have been solved." I think it depends on many things, including the size of the market. I'm willing to bet there are many profitable niches which are served currently with only sub-optimal products. But to find these one needs domain knowledge od the niche, and I think these are served best by teams of adventurous established experts rather than teams without domaim knowledge.