Tell me you've never worked in fintech without telling me you've never worked in fintech :)
Decimals aren't enough. You have frequent currency conversions and all sorts of other chores. Using a fixed-decimal datatype doesn't solve those problems by itself, it's just a tactic.
Yes, I never worked in fintech, but lots of my family members work or worked in banking sector. So, I'm not an alien when it comes to money, and how it works and processed in IT side of the things.
Decimals aren't enough. You have frequent currency conversions and all sorts of other chores. Using a fixed-decimal datatype doesn't solve those problems by itself, it's just a tactic.