As for “blockchain”, yes they do. That’s the main goal of MIT’s DCI digital currency initiative. The director, Neha Narula, testified to Congress on camera that they can make a CBDC blockchain better than Bitcoin. (Which they obviously can’t.)

As for making it more centralized, commercial banks won’t allow it. They’re the main Fed shareholders anyway. They profit too much from the status quo. Centralize by absorbing commercial competitors, sure. But disintermediate themselves? Never.