I don't know, what is the point of anything other than not offending or hurting peoples feelings.
(IFF) "straight talk" does NOT spare people's feelings and or mitigate misunderstanding (THEN) it seems to be no more and or no less efficient than "normal talk"
I remember a story about some american businessmen who were frustrated by a meeting with chinese businessmen.
The chinese invited the visitors to an elaborate dinner and peppered them with questions about topics **seemingly unrelated** to their business interests.
The americans wanted to "get to the point" and "talk dollars and cents".
What they didn't realize is that it is often more accurate to slowly and carefully define what something is "not" instead of trying to dive directly into what something "is".
The chinese businessmen thought the americans were hopelessly childish and naive, and the americans thought their hosts were being intentionally obtuse as part of some specific strategy to "throw them off their game".