Have you ever rebuilt and repaired old electrical appliances? An old microwave with a turn dial timer is most certainly not electronic. Electrical sure, but not electronic.
Those only basically have a mechanical timer dial, high voltage transformer, high voltage diode, magnetron, light, fan, turntable motor, fuse, and some safety switches for the door.
Absolutely nothing electronic about them, they’re as dumb as an old-school toaster, they just happen to use high voltage to generate microwaves instead.