“Don’t put metal into the microwave” requires neither a thick manual nor theoretical underpinnings of electromagnetism. It requires a warning sticker.

Incidentally, there are types of metal dishes that can go into the microwave and yet most people today don’t know that, probably because nobody actually read the manuals, just the warning stickers.

I am by no means against understanding the theory behind what you are doing. My degree is in physics for a reason. But the “older is better” adage is tiring. I guarantee you that most people didn’t read the 200 page manual for their microwave oven and neither would most people today.