(x402 author here) Thats actually exactly what the intention with x402 is. Merchants express to the buyer multiple ways that they accept payment and the buyer chooses the one they prefer. As of right now stablecoins on various crypto rails are the major form (largely because they're the easiest to start with from a development standpoint), but as Cloudflare indicated in their blogpost, they're proposing a scheme that uses deferred payment via credit card or ACH https://blog.cloudflare.com/x402/.

Thanks for stopping by.

Hi Erik. Frankly, I wonder if this is an elaborate joke since there are some serious concerns in terms of CVP ("wait two seconds and retry"), in terms of gatekeeping potential nobody will sleepwalk in to ("we solve two the second wait with our CoinbaseCoin, get an enterprise subscription!"), or in terms of the inherent lack of openness in HTTP these days (client/server, HTTPS identity chains, DNS, gatekeepers like CloudFlare). For thoughts on a more open protocol without these drawbacks see https://raw.githubusercontent.com/globalcitizen/ifex-protoco... Sincerely, architect of a predecessor exchange (founder asked me not to continue work on open protocols).