English is an official language in 35 countries.
The UK, the US and Australia are not among them.
Official languages are more important in countries where there is either great linguistic diversity or two or more major languages competing. Of the 7100 (or so) living languages about half are expected to die out by the end of the century. Chinese, Hindi-Urdu, English, Arabic, and Spanish have the largest numbers of native speakers, with Chinese alone having more that the third, fourth, and fifth languages combined.