Because in practice services like TransferWise solved this problem using fiat currencies with fees low enough not to make it worth bothering with crypto.
Looks like other people still trying to solve as well:
> Earlier this year, Coinbase changed online payments forever with a new protocol called x402. But could this technology really usher in a new age of 'machine to machine' payments? Let's run it...
Let me introduce you to the wonders of Discover.