Oscillators are supposed to oscillate but when you want them to, they don’t resulting in debugging.

Amplifiers can have a big phase shift and gain which fulfills barkhausen criteria which is the fundamental requirement for something to oscillate. Oscillating amplifiers are usually a very bad problem because it trashes the signal you are amplifying and tends to suck up a lot of power.

Fuses take a glacial amount of time to blow compared to an integrated circuit. When something goes wrong the IC blows up way before the fuse goes.