The trick is imho that each person has some "bottom limit" of where they don't care about that money below that line and are happy to send it to a good cause.
I don't mind sending hundreds of sats to a podcaster, because it's smaller than a number I'd consider for a tip in a restaurant... but then I get urge to use boostagrams, because it's convenient...
I think there is a potential for a business models in this direction - and as an added benefit it will train users to be ok with paying micropayments for things as they use them.