Sure, I don't see how FETs having a common failure mode of passively conducting is exceptional though? You've got to design (and test) for likely failure modes.

Sure, I don't see how FETs having a common failure mode of passively conducting is exceptional though? You've got to design (and test) for likely failure modes. Like even if you use a linear regular, you should be thinking about what happens when there is a short downstream. The problem with fires isn't the type of circuit per se, but rather that anything connected to the mains can unleash a significant amount of power. And that designing/building for safety increases cost, for additional components or even things like larger PCB area for creepage. We basically take a lot of the work that goes into electrical safety for granted.