I just don't understand why are you referring to the old human being as the idiot and illiterate one.  Because not every old human being is an idiot. They are not newborn babies they have spent a life and are near to an end. I t doesn't mean, they have no intelligence to understand what are digital wallets (hot and cold) and what are private keys and public keys.

If you could teach them in a good manner then there is no chance that they will not understand the concept. They might disagree with this technology and could say this technology is not good etc. But they will understand blockchain technology and how it works in general.

I agree with you about most of the old human beings gets fall prey to scams and in frustration, they do not accept them. The reason is simple, they do not learn before usage, and they need someone to teach them if they are not YouTube learners.

Here is a thread in which one's uncle took a loan to invest in crypto, your question could be backed up with this topic. Taking loan for investment can be life threatening

Old people make these types of mistakes and then their offsprings have to face consequences. If there is the mainstream adoption of BTC is going to happen then a complete guide is necessary for kids to old men.