You might need to prove your knowledge of the English language if you’re 18 or over and applying for citizenship or to settle in the UK (known as ‘indefinite leave to remain’).

You can prove it by having either:

• an English qualification at B1, B2, C1 or C2 level
• a degree taught or researched in English

https://www.gov.uk/english-language

A. Educational Requirements

An officer administers a naturalization test to determine whether an alien meets the English and civics requirements.[1] > The naturalization test consists of two components:

• English language proficiency, which is determined by the alien’s ability to read, write, speak and understand English; and

https://www.uscis.gov/policy-manual/volume-12-part-e-chapter-2

They already do it, there is no double standard here.