From my first year as an undergraduate student, there was this story a professor told us about top-notch computers taking weeks to fit a single linear regression model, back in her days as an undergrad student. I recall thinking, It's lucky that today's computers can run it in no time. This was naive though. As the history of computing shows, every time a faster horse is born, a more challenging track is built.
Computers have advanced a lot and so have the models—thankfully. In addition, our capacity to gather data has improved by teraflops. The first time I felt the need for cloud computing, I had designed a model so huge that I couldn't load it and the data simultaneously. It was either one or the other. Using a cloud service, this problem became manageable.