It's not necessary, it's just extraordinarily convenient. I don't have to ever say, "Oh, wait, I'm on my laptop now, I can't run an application with 100 process

It's not necessary, it's just extraordinarily convenient. I don't have to ever say, "Oh, wait, I'm on my laptop now, I can't run an application with 100 processes without causing my system to grind to a halt." Even the sequential performance of the remote systems is much higher than my laptop. The system in front of me is a means to interface with the real system, and has been for a long time. Granted, I have worked on parallel and distributed languages and runtimes for most of my professional life.