If I was living in a world where there are zero observed apparently-very-lucrative deal” that turn out to be scams then I hope I would conclude that there is some supernatural Creator who is putting a thumb on the scale to be sure that cheaters never win and winners never cheat. So I would invest in Ponzi Pyramid Inc. I would not expect to be scammed, because this is a world where there are zero observed apparently-very-lucrative deals that turn out to be scams. I would aim to invest in a diversified portfolio of apparently-very-lucrative deals, for all the same reasons I have a diversified portfolio in this world.
In such a world the Epistemologist is promoting a world model that does not explain my observations and I would not take their investment advice, similarly to how in this world I ignore investment advice from people who believe that the economy is secretly controlled by lizard people.
The play pump hypothetical/analogy is a bit forced, in that I’ve not heard of people making lifetime commitments to give money to a specific charity. I think there are good reasons for that, one of which you mention. People do sign up for monthly donations but they are free to cancel them at will, legally and ethically.
I wonder, if Austin aged 27 gave a short presentation to Austin aged 17, would this be enough to convince the younger Austin not to be confirmed Catholic? I think the younger Austin would be sympathetic to his older self’s complicated relationship with the church. Maybe he would offer “stop going when it’s no longer good for you”.