The English language, as we know, has many rules, which need to be applied for precise interpretation. For people who are not native English speakers, the proper presentation of their ideas is quite challenging. English is the accepted language for most publications. Minor flaws may create bad impressions and cause difficulties in understanding the context. Thus, clarity, conciseness, grammar, punctuation, and brevity play vital roles from the English point of view.
Thus, it must be ensured that any information published on the internet or on paper is completely flawless and conveys its intention without ambiguity.
I am one of the numerous individuals who have adopted language editing as a profession to cater to the needs of thousands of intelligent minds who excel in their respective fields but are held back because of the English language barrier.
Certainly in a business or professional setting, improved language skills will provide advantages.
As far as general conversation with non native English speakers goes though, I meet many tourists and language students each summer where I live, and I don't think 'perfect' English is so important. The vast majority of my social circle are monolingual and are usually impressed enough with anyone trying to speak English that they will always try to help, even with the use of hand actions or statements reduced to key phrase words.
I think a large percentage of British folk secretly wish they could speak another international language, but lack the motivation to learn because it's so easy to get around the world relying on English.
In remoter parts of the world I have sometimes asked immigration officers for the words 'hello' 'goodbye' 'please/request' 'thank you/thanks' 'sorry/apology' 'yes' & 'no'. I then wrote them down in my own visually recognisable phonetic way.
Those few local words combined with hand signs and drawings in a notepad definitely helped.
But I was especially grateful to the (sometimes few) people who had learned even the English of a small child.
For that reason a persons effort is more important to me and I tend to be less concerned about structure and grammar.
With Eastern European friends of mine here, sometimes their English is actually of a higher standard and more formal than many English people I know. I've often been asked to help explain slang words and prases, or to help make them sound more informal.
I also know others who struggle with English, but I'll always help any decent person who's had the courage to throw themselves into another culture while still only a basic student of the language.