I agree, but the unfixable+immortal combination isn't really an acceptable situation.

The solution for most devices is to simply keep them off the internet. Being a host on the internet requires some level of care and maintenance so you don't become a hazard to others. I doubt most light-bulbs or thermostats are worth the ongoing expenses of maintaining security updates into the indefinite future. In theory, traditional goods that last more than a few years should be more successful on the market than self-destructing devices with dubious internet features.

This is fine, there is a market for that like anything else. The problem is where that is not a function the consumer is aware off at the time of purchase.

Now perhaps some good recycling laws would combat abuses of such an effect.