Anecdotally, most founders are extremely busy and much of their financial success is in finding product/market-fit to maximize equity value. Therefore, learning about maximizing interest and managing dozens of bank accounts to minimize insolvency risk didn’t seem like a good use of time. Parking cash in SVB, which had been around for 40 years (with some investors even requiring startups to bank with them), seemed like a safe, secure option. Obviously, hindsight is 20/20 here.