Blockchain scaling is still a very active area of research, and anyone (like GP) telling you there's a battle-tested solution available today to replace Visa is lying to you.
On the precise issue of transaction cost predictability, I think most solutions would revolve around creating a market for the ability to execute future transactions. There's a hackish project on Ethereum doing just that: https://gastoken.io/
On the precise issue of transaction cost predictability, I think most solutions would revolve around creating a market for the ability to execute future transactions. There's a hackish project on Ethereum doing just that: https://gastoken.io/