Certain industries require significant expertise to compete effectively (FinTech is a good example). Finance itself is highly regulated and highly dependent on detailed models used for valuation, risk assessment, or accounting. Each of these are context-sensitive. While it's possible to learn some of this from books, seeing how these play out in a competitive environment gives us extra insight. Some areas of finance have high degrees of product innovation, such as derivative markets. On top of that, technology itself has been changing rapidly over the past few decades. Founders entering this market would be wise to consult with experts in areas where they feel it will help generate additional options that they hadn't considered.