Required for a successful VC-funded shooting-for-the-moon startup, maybe. Not required for a successful web app. I paid off my student loans and put a downpayment on a house with a "add reviews with star ratings to your online shop" app. I have no passion for ratings widgets. I also now host contact forms for ~1 in 20 Shopify stores; I have no passion for contact widgets. They're just products, that happen to solve problems for some people that value the solution. Solutions to most business problems aren't complicated, thousands-of-hours undertakings.