> The "fundamental distsys problem" here originates in the language level: the problem is the attempt to hide the existence of a network protocol from the application code.

so the problem isn't about whether or not the application knows a network protocol is involved. it's that state has fundamentally different semantics when any network protocol gets involved.

languages, SDKs, etc. all exist "on top" of networks in the abstraction sense, once you start sending bytes between nodes over unreliable links then that stuff dictates the rules that you gotta abide by, you know?

Sure. And Cap'n Proto/Web provides tools for handling that. And they work, as evidenced by one of the largest and highest-traffic distributed systems in the world (Cloudflare Workers / Durable Objects) being built on Cap'n Proto.