In simple circumstances, it's easy to tell if on net the value is greater than the cost.

In complicated circumstances (balancing lots of different sub-components of different types) it can be considerably more difficult.

In those situations, a thing that looks like a no-brainer might actually be a bad idea.

Situations that "should" be simple can sometimes be accidentally complicated; a kind of "gerrymandering".

Making it so the important decisions are easy to make well with few moving parts is a form of paying down debt.