Like, I’m “fluent”, but a lot of the people I want to speak with can’t understand what I’m saying
My partner doesn't speak English as a first language and I do. I am also a master's student who has learnt to value a particular kind of speech complexity, and as a result he finds it significantly easier than I do to understand and be understood by other people whose first language isn't English (wherever they are from).
That encompasses the majority of both of our colleagues and mutual friends, and I consider him to have a kind of fluency that is important and that I lack, at the same time as I have a kind of fluency that he can't replicate (not least because he hasn't spent 8 years reading variously jargon-fuelled (often translated) sociology (etc.) texts). He has a kind of fluency that is particularly important to me as I intend to work support migrants in the UK and I can't quickly learn all languages.
If fluency is about communicating clearly, then mine is situational. The language flows in different ways.