Those of us who’ve used computers for a while remember when we did our work at ‘dumb terminals’, which did nothing other than connect us to the mainframe. Often work was submitted in batch to a service bureau which processed all the transactions at night so we could get updated reports in the morning.
The pendulum then swung to having all the software and data in the workstation at your desk. That requires a far more powerful machine and eliminates reliance on the service bureau. The mainframe was less important in the era of distributed computing.
My friend John Bredehoft has a thoughtful post on the swinging pendulum in computing, What if you don’t know that you’re living in the cloud?