They will never get the defederated aspect of the fediverse. It’s like speaking some alien language to them, it simply does not compute.
It's really not that hard to explain. Just tell them it's like email, they'll get it.
I swear, most techies think that non-techies are another species. It's not that hard to explain things, and not everybody is as incompetent as our mothers. Young people understand technology better than old people, not worse, not sure how that part has you confused.
But yeah, being able to post photos directly without going to imgur is easier and more intuitive, I'm glad it seems to be built into kbin without any issue.