Bitcoin's primary innovation isn't the blockchain per se, but the combination of the blockchain and proof-of-work timestamping to solve the double-spending prob

Bitcoin's primary innovation isn't the blockchain per se, but the combination of the blockchain and proof-of-work timestamping to solve the double-spending problem without requiring a central authority. A "private" blockchain largely defeats the point, as you don't need trustless distributed concensus when you implictly trust yourself or a central authority. We just call these versioned databases.