There are only two ways to transfer money in the US - cash and FedWire. Everything else settles through one of these.
Cards - settled via FedWire
ACH - settled via FedWire
Checks - settled via FedWire
Venmo - settled via cards/ACH (see above)
Local drug deal - settled in cash.

It has always been this way. Originally international wire transactions would be settled by shipping gold between countries. WWI put a stop to that since the Germans were sinking too many ships. But central banks still settle transactions occasionally with gold payments.

This is much easier to do now because
1) The Germans aren't sinking ships
2) Most central banks hold a large chunk of their gold reserves at the New York Fed.
The NY Fed's gold vault holds 6000 tons of gold (3% of all gold ever mined) https://www.newyorkfed.org/aboutthefed/goldvault.html

So when the central bank X wants to pay central bank Y and doesn't have enough IMF SDRs or a credit line from the Fed, sometimes they'll call up the NY Fed and move gold bars from one numbered vault to another vault. The NY Fed only charges for transactions, not for storage.

The corollary is that old payment systems never die. They just become a niche settlement system. The Yapese still use stone money in traditional ways. And I wouldn't be surprised if somebody in the Middle East is still doing transactions in Barley. https://www.ynharari.com/topic/money-and-politics/