My microwave will not end up as a subscription platform. Maybe if I have to buy a microwave some day, but I don't know why I would have to do that. My microwave works fine.

Microwaves don't live forever (especially newer ones). At some point the choices will be:

[ ] a connected microwave

and

[ ] no microwave

Just like almost all newer cars now have some kind of wlan connection to the factory built in.

This twelve inch cast iron skillet, on the other hand, will last forever.

Yes, it likely will (unless you drop it, or quench it). But if you're careful with it it will last longer than anybody reading this. But just like car batteries: cast iron skillets rarely die, but lots of them are murdered.