Layers exist in finance for the same reason layers exist in programming: because value is being provided. Or, at least, that’s what the Efficient Market Hypothesis would say. Maybe you can’t see the value as an outsider, but you know, Chesterton’s Fence. Only when you see the value of the current system should you be allowed to change it.

Using the example of mortgage backed securities, they were created to solve real problems. Mortgages carried risk, were too unique. Also money had a hard time reaching those who needed mortgages. Most mortgage providers were local and often there were too many people who wanted mortgages and not enough money, or the other way around. By packaging mortgages together, you could reduce risk and sell traunches nationwide.

TLDR: understanding is a prerequisite of change. And just like software, if you can’t find a reason for why something exists you should probably look harder. More likely than not, you are the one who doesn’t understand, not the person who created the thing in the first place.