There are lot of MCUs around us but they are locked down and not reprogrammable. For example, if your microwave oven or a smart bulb breaks, you cannot reuse it

There are lot of MCUs around us but they are locked down and not reprogrammable. For example, if your microwave oven or a smart bulb breaks, you cannot reuse its MCU for anything else. Don't you think that MCUs must be reprogrammable, resolderable and reusable?