No matter what they do with your money, they are expected to keep it as it was, at least nominally (maybe with a little interest).

Bank runs and bank defaults can be possible but are far far far far rarer than yourself investing and losing your money.

So your argument is like:

"You think chainsaw-tied-on-your-head-skiing is dangerous and you'd rather stay at home? Do you know how many people die at their homes?".