... what happens when the decentralized version of things becomes easier to use than the centralized counterpart? You are not accounting for this.

I am. I made the switch to being paid in crypto for my software nearly 3 years ago long before the crowd started doing this. We have 1% adoption at best currently. Once the majority of people are accepting payment in crypto they will not feel the need to exit to fiat. We need 1 or 2 bull cycles like 2017 to achieve this.

So let's hope you're right and that people won't stay lazy or complacent about how they are getting paid and can take full responsibility by being their own bank. A tipping point destabilizing the dollar and other national fiat might achieve this.