It's actually quite difficult to get utilization up past about 60% on average at a large scale, and when utilization increases efficiency decreases (from missed

It's actually quite difficult to get utilization up past about 60% on average at a large scale, and when utilization increases efficiency decreases (from missed clock turbo opportunities and other microarchitectural feedback). So if you are using half a percent of your nominal capacity that's 1% of your total CPU usage. 1% is a lot at scale. For example at Google's scale that would be enough to justify a team of several full-time engineers to find a more efficient way to do it. Even saving 0.01% of CPU time is considered a pretty good outcome at large companies (Amazon, Microsoft, Facebook, ...).