US banks created Zelle, with free instant transfers via your banking app. It’s a shame more people don’t use it. Otherwise people just use credit cards for paying for stuff.
If Zelle cannot make the transaction happen, it is out of the running. Full stop.
I've noticed a "fee: zero" statement on the transfer page recently. I expect there will be an actual fee in the near future.
It may change now that businesses are allowed to pass on fees.