I think people don't like to think about this too much.
You can apply it to all sorts of things - How you behave, what you buy, things you do, who you vote for, what you eat etc.
It applies to climate change, community, human rights, animal rights, health etc.
If people thought about these things a little more then perhaps the world would be a better place.
To answer your example, no I absolutely wouldn't send a child who I knew was infectious with COVID to school. But then I am one of the few people who still wears a mask and tests for symptoms etc. because I do think about this a lot (I have a post viral illness and would hate to be the cause of this for someone else and do not want my own condition to deteriorate either). I know not many people think like me, even if people wore a mask when they have symptoms it would be something but I don't even see many people doing that, it makes me feel sad and frustrated and damages my trust in others.
I do think a lot of people feel powerless about many situations though (I feel this too) eg, I do what I can for climate change, but I still run a car because I can't manage without one. And I can't afford an electric one, don't have a driveway to charge it etc.
I am vegetarian, but I should be vegan if I followed that ethical position through etc.
So I do what I can and try not to think of the rest. I think a lot of people just don't think about things too much.