> Free and open payments should be bitcoin based to be truely decentralized

Agreed. Which is why 5 years ago, I developed L402 (formerly known as LSAT) to fill this very gap:

  * https://github.com/lightninglabs/L402 (https://lightning-labs-2.gitbook.io/lsat)

  * https://lightning.engineering/posts/2020-03-30-lsat/

L402 is more opinionated as utilizes the Lightning Network (LN) directly within the protocol. The server presents the client with a SHA 256 payment hash embedded within an LN invoice. The server requires the client to present the pre-image for said payment hash. The only way the client can obtain said pre-image is by paying the invoice on the Lightning Network (all payments are conditional payments where a pre-image needs to be revealed to complete a payment).

L402 also adds a layer of macaroons, enabling the protocol handle both payment and fine-grained authentication.

The advantages of LN over something like Coinbase's Base chain include:

  * Privacy: Coinbase and the entire world sees all your transactions. 

  * Decentralization & Reliability: Base is a singleton instance, if it goes down, you can't make any transactions. LN is decentralized, just like the internet, you can always route around failures. 
 
  * Settlement Speed: Base blocks happen every 2 seconds, until that period your transaction isn't finalized. However that's only committing to Base, and not the underlying ETH chain, which has 12 second block time. Latency on LN is primarily a function of e2e network delay, so it can be as little as 100 ms.