As above; ARM grew from a very low-power beginning (some 250mW total for the original ARM-2 chipset of CPU, IOC, MEMC, and VIDC, running at 8MHz on 2 micron tech, in 1989), and has remained low-power since. Whilst the CPU’s obviously only a part of any server, I’d imagine that the savings in power usage across as many servers as companies like Google and Facebook have are the driving force behind these evaluations.
