> Or do we just say "If they're not on Kicktreonattrpaymo when it's on my mind I guess they don't want my money"?
Yes. I don't owe them a business model, they're the professional here, it's their job to be where I want to pay them.
> And I know that my ledger's clear and doesn't depend on when I decide to get around to kicking a donation over.
There's no ledger here. If you want to pay them, pay them, if you don't, don't. If that wasn't an arrangement they were content with, well, revealed preferences.
> If this is all about convenience, Spotify could probably largely solve the economic problems by bumping up what they charge 5-10x and directing additional listener revenue by specific listener choices.
What economic problems? There's no shortage of content being created, so evidently the deal for creators isn't actually that bad.