Buf's goal is to replace the current paradigm of API development, centered around REST/JSON, with a schema-driven paradigm. Defining APIs using an IDL provides numerous benefits over REST/JSON, and Protobuf is by far the most stable and widely adopted IDL in the industry. We've chosen to build on this widely trusted foundation rather than creating a new IDL from scratch.
But despite its technical merits, actually using Protobuf has long been more challenging than it needs to be. The Buf CLI and the BSR are the cornerstones of our effort to change that for good and to make Protobuf reliable and easy to use for service owners and clients alike—in other words, to create a modern Protobuf ecosystem.
Can confirm that the protobuf CLI is pretty terrible and confusing as heck. Haven't used this, but seems neat.
Recently (feb 23 2022) hit 1.0:
There's some sort of commercial offering, not sure exactly how that works