I see your point. Even multithreading can be seen as a form of distributed programming. At the same time, in my experience these parts can often be isolated. You trust your DB to handle such issues, and I'm very happy we are getting a new era of DBs like Tigerbetle, FoundationDB and sled that are designed to survive Jepsen. But how many teams are building DBs? That point is a bit ironic, given I'm currently building an in-memory DB at work. But it's a completely different level of complexity. And your example with writing a file, that too is a somewhat solved problem, use ZFS. I'd argue there are many situations where the fault tolerant distributed requirements can be served by existing abstractions.