The point is, there's not need for everything to be 100% reliable in this context. If a fire destroys everything and their computational resources is unavailabl

The point is, there's not need for everything to be 100% reliable in this context. If a fire destroys everything and their computational resources is unavailable for a few days, that's somewhat okay. Not ideal, but not a catastrophic loss either. Even data loss is no catastrophic - at worst it means redoing one or two weeks worth of computations. Some sort of 80/20 principle is at works here. Most of the costs in professional cloud solutions comes from making the infrastructure 99.99% reliable instead of 99% reliable. It is totally worth it if you have millions of customers that expect a certain level of reliability, but a complete overkill if the worst case scenario from a system failure is some graduate student having to redo a few days worth of computations (which probably had to be redone several times anyway because of some bug in the code or something).