Mostly agree with you, but:
> My own parents are still relatively young and my in-laws are sceptical enough of other people that it’s currently safe but it won’t be so forever.
It is always interesting to me how people equate getting old with becoming dumb. I know there is definitely some age related decline that's inevitable, but if a person has grown up with computers, and maybe more importantly, has had a hacker and curious mindset while younger, it is not likely that they will suddenly become so naive and vulnerable, even when like 80.
What usually happens is that people lose interest in learning new things and keeping up. My own mom (who passed at 73) could never be convinced to use Whatsapp messaging, thinking it is something complicated for the young ones, and yet I currently know people in their mid 70s and even much older who are still as sharp as anything and use all the cool apps.
Sadly there’s also dementia where a gradual decline occurs. And I’m pretty sure learning gets harder.
I assume you didn’t have experience of your older relatives being targeted by professional criminals. I’m not talking about online honeytraps, in some countries these gangs will mix offline and online schemes (e.g. pretending to be social workers, driving my grandma to the bank, buying her a new smartphone to get access to her online banking, which were stopped by her luckily “forgetting” her current smartphone/banking PIN code).
That’s for Eastern Europe. I heard a similar line of reasoning for banning rooted phones in Asia and it’s easy for me to relate to that. It seems as if first-world hackers here just don’t grasp how low criminals can and will go.