>We’re three decades in with the web and it’s pretty clear that voluntary payment nudges don’t work. Most people won’t pay for free content after they’ve consumed it.

Humans have no problem tipping, the issue is that a single article or piece of content is rarely worth than a fractional amount of whatever your preferred currency is, and it costs more than that amount to transfer that currency. Sponsorships work because you pay normal amounts of currency to receive a larger future block of content.

To make tipping work, you need a system that supports allowing you to deposit normal sums of money but then dole it out in micropayments, and also not charge more than those payments for processing the micropayments. A payment system like Paypal, that maintains an internal balance that is used instead of just transferring from one bank account to another (zelle, venmo), could handle this but I don't think the financial incentives are there for them to bother with it.