I think the flip side of this is Facebook or wherever the link was pushed to your in-laws (which is what I'd guess happened) feels... empowering. Those apps are literally optimized, with billions of dollars (and extensive science, especially psychology), to validate folk's views in the pursuit of keeping them clicking. Their world's telling them they're right; of course your retort will feel offensive and wrong.
They're in a trap.
And I still see lot of scientists posit 'why is this happening?' unironically on Twitter or something, which really frustrates me.