Is the number huge, though? Retail stock-picking is done through mutual funds and active ETFs, which are typically owned by a larger outfit like Blackrock or Franklin Templeton, so the active stock picking is done by a select few managers of the fund. If that goes away, Blackrock or FT can still sell indexes and variety of bond funds.

On the hedge fund site extreme churn is fairly typical and considered part of the job. Well-known pickers (known mainly due to their windfall successes of the past and survivor bias) like Stephen Cohen, Carl Icahn and John Paulson are motivated less by the need to live paycheck to paycheck and more by the gambler's high.