Most accounting systems are based on two decimal systems. Unless you work in a particular subset of technology systems the concept of building with 3 or 18 decimal systems is a borderline ridiculous thing to discuss with someone who does not.
Money is for most of humanity a 2 decimal system. I’ve always had this 2 decimal rule in my head even though I’m not sure anyone else thinks of it as a rule. Once a systems costs are sustainably below the 2 decimal threshold the number of use cases for it increase dramatically. It’s also much easier to subsidize.
The most famous example of this (I am aware of) is FedACH pricing. The FedACH pricing isn’t a secret, it’s hiding in plain sight.
A typical ACH transaction costs less than a cent but that pricing rate is extremely difficult to get. New participants have been trying to get in for years and it rarely works.
What is so fundamentally different about protocols hitting these cost thresholds is that everyone can access them. You could spend 10 years trying to get the fed pricing above but you can access the protocol pricing below in a few minutes.
What also feels striking to me which may not be immediately clear is that I don’t think these systems really compete for use cases. Now that there is price parity between them it makes it a lot easier to build experiences that include both without interruption to the end user.
When the infrastructure costs are similar between providers it’s much easier to have a uninterrupted user experience.