I work in a very boring industry very far away from SV and spinning up and down machines for doing calculations and analysis is a godsend. I have a 'cluster' of 6 machines with 128 GB of RAM each set up and ready that I can start up with a script and only pay for the less than 200 hours a year I actually need them. Sometimes however I need 256 GB of RAM so I just change a parameter in my script and, magic, I have 256 GB of RAM. For other workloads the optimal setup might be 100 1 core machines with 2 GB each. So I type some commands, and now I have that instead.

And since it's my 'private' cluster I don't have to worry about queuing my jobs and waiting for the machines to be free. There is no way my department would have bought me those machines as physical hardware.