Don't listen to others, "fair enough" here has nothing to do with "公平" or "公正"!!!
Fair enough simply used to say that you agree with someone's suggestion or that something seems reasonable, you can say "有道理" in Chinese
A: Dude, why didn't you take that job? The benefits were killer! 兄弟,你怎么不要那份工作,薪酬那么好!
B: Maybe, but it was so far out, I'd have spent more on gas than what they were willing to pay me. 也许,不过太远了,还不够油钱呢
A: Fair enough. 有道理
if you say"很公平",it doesn't make any sense and people would be confused by asking you "什么很公平?"