The way we use computers changed. The hardware didn't.
Mouse and keyboard held for forty years. Then agents arrived. Typing became the slow way to work. Tracking which agent is doing what, on which machine, became a full-time job — Harness is the device for that.
Skip typing, just say one sentence. The work goes to the right agent, on whichever computer or server it lives on. It drives every agent you already use, and the newest ones.