Idk I think everyone is dumb somewhere and I dont think people can generally identity where that is.

Do you not know how aging works?

Yep. Our parents always told us to not believe everything on the internet.

And now, they believe anything from some random shitbag overseas.

It kind of is. There is are a lot of people in the early stages of dementia or Alzheimer's who get easily confused and are aware that they can't trust their own memory. It's very easy to see how they could be talked into trusting someone they shouldn't.

the inherent knowing-that-you-don’t-know.

Something that the boomer generation is notoriously shit at

You can wither use a credit card responsibly, or not have one. Credit card companies could probably do more here by making an "old person card" that can't be used to make online orders or phone orders, but until then, these people shouldn't be using credit cards with high limits.