Just because you don't understand it doesn't mean it isn't useful. For a trivial example, I often use calculus to measure rate of change of telemetry of production systems, and that's just as a simple developer measuring performance of things I'm responsible for.

I assume by "order of magnitude" you're talking about big-O and friends... I use that math all the time when I deal with things at scale. If you're doing anything that's not a CRUD app with a trivial amount of users, you quickly run into math.