BYAS was built to be on chain.

People aren't used to managing their money. They are used to giving others control. This makes them feel safe. And if anything happens, they are able to blame someone else. There is also the "illusion" of safety with certain guarantees from (for example) banks. Even though there are countless examples of banks not adhering to their guarantees. When you give others control of your money you are skating on thin ice as people say. You are one Lehman Brothers, or other financial crises away from losing everything.