Bismuth originated as a single-file code base. It grew to become a powerful engine after many thousands of updates & code iterations. With Bismuth2.0, it was time to consolidate, organize and clean up to get better control of the code, permit easier maintenance and streamline external work on the code. Regardless of the core overhaul, the new V2 code base will retain full compatibility with legacy nodes. Legacy support may be dropped at one point in the future once Bismuth2.0 has fully transitioned.