People have career and ego incentives to overestimate the constraints of the environment they're working in, and will use lazy heuristics like rounding some number to "a lot" and assuming that it justifies pulling out all the stops. Computers are fast. One or a few of them can accomplish quite a lot. Some people really do exceed those limits, and godspeed to them, but even in the companies they work at, the vast majority of applications do not.