Families are complicated, aren't they? I don't know for sure, either, but, in our case I lean towards the fact that they showed they don't *really* care about their grandkids if going to the grocery store when they could easily afford delivery is a dealbreaker for them. Like you said, they made that choice years back now. Thankfully my wife was aware enough to tell me straight up front in 2020 that we couldn't trust them to tell us the truth about their exposures and she took control of the situation with her family.
The running theme that I've noticed posting a few "my life in a pandemic" type posts is that there's a lot more people out there than you'd suspect who, literally, will not change anything in their lives, particularly if it's even slightly inconvenient. COVID, climate, etc. it doesn't really matter how big or small it is, and there's always going to be "leaders" and peers who encourage them along that path, too.
@BE @colorfiend Some of these people may lack the ability to adapt to any change. I’m seeing similar reactions on the Nextdoor app. Colorado’s energy provider announced rate increases for gas and electric in Nov 22. People are screaming about the new meters and bills they just received. Many refuse to turn down their thermostats, wear sweaters or avoid using electricity during peak periods. They say they refuse to be uncomfortable in their own homes.