You're mixing disciplines. Separation of concerns is a computer science principle. It very much doesn't happen much when one is designing analog electronics, w

You're mixing disciplines. Separation of concerns is a computer science principle. It very much doesn't happen much when one is designing analog electronics, which is where fuses come up. If I'm designing a piece of medical equipment, it cannot kill a patient with any single point of failure. That's a systemic design issue, and any device, including a fuse, has to be seen in the context of the system it's plugging into. It'd be possible to separate concerns, but it would result in grossly inefficient, over-engineered systems. You do get a bit more of that in electrical (rather than electronics) work, since you need to count on idiot contractors who will screw everything up.