I must politely disagree with that. It may be that we have been to distinct types of CS programs.

Some of my work as an under grad was taxing on my computer and much more so as a grad.

Even simple things like compiling a system can quickly get taxing and slow.

Some classes require models, algorithms that takes a lot of power to process or to prove.

My master thesis was system would run for 48 hours on the desktop I had then, after some optimization got it down from 65 hours.

Ideally though you have access to a lab / server that you can offload your hard work on.

In my experience those resources were already under maximum load during most of the day and parts of the night.

Being able to just run them locally was convenient.