As a systems person you don't see any benefit to having different layers? Currently you are getting to watch the issues of shoving everything into layer 1 play out on Ethereum. Bitcoin isn't just a distributed system, it's value is derived from being a decentralized one.

Almost every technical aspect of Bitcoin that people like to claim makes it "old technology" or inefficient were purposefully chosen trade offs with decentralization. It's obvious that a single centralized database would beat every cryptocurrency on transactions per second.