It can be useful to say that everything is a distributed system because it actually matters in a lot of contexts, just not for CAP. There are sorts of networks

It can be useful to say that everything is a distributed system because it actually matters in a lot of contexts, just not for CAP. There are sorts of networks within a single machine or even a single CPU, and generally "further apart" things have more latency between them. For example, task on <cpu 1, core 1> talking to another also on <1, 1> vs <1, 2> vs <2, 1> vs all the way off on the GPU... A single failure probably takes down the entire system, but not necessarily.