I think there's more to at least one of the examples mentioned. Comparing a drowning child within your reach, to a child in a far off country that can be saved for just a $5 donation. The child drowning is an event you have agency with. You, yourself, are going to the river and pulling a child from it.

But the $5 donation... That child you will never see, and if you do see a picture of them, what chances are that you'd believe that that's that child you're saving, and even if you do believe, will you ever see them again? Can you be 100% certain that every cent of your $5 is going towards the purchase and administration of that life-saving vaccine to that child? That child that, you're not even totally sure is real, or needs saving? We've all heard about scams, and scams disguising themselves as charity aren't new either. Hell, our president and his entire family is no longer allowed to run a charity within the state of New York because they were laundering money through their "charities."

I think when we can actually see the problem, and we have real agency in the situation, then it becomes a moral imperative to act. But to act as a third party, whilst never witnessing the problem, or the person being helped... That's not a moral imperative. You don't have agency in the situation, someone else does. You're not witnessing the problem, you're hearing about it through the TV or internet. Are you really interacting with the problem, in the Copenhagen Interpretation, by hearing about something through a third party? I would say not.