"Low-hanging fruit" immediately brings to mind both the story of Tantalus and the Aesop about the fox and the grapes (both of which involved the opposite). Investopedia claims

Phrases such as "fruit low hung" and "fruit hanging low" has been part of the English language since the 17th century, but the exact phrase "low-hanging fruit" likely first appeared in print in a 1968 article in the Guardian newspaper, and the phrase referenced something easily attainable.

Certainly it has nothing to do with "strange fruit".