When people give the conclusion/recommendation last, it feels like they’re either disorganized, have a low estimation of others, or are trying to control the outcome with unnecessary persuasion.
The right recommendation usually can stand on its own and eliminates all that buildup. Try it sometime.
Executives who typically want “conclusion first” for “time savings” often use up the same amount of time or more “backing through the needed explanation.” Does that mean you shouldn’t aim to be succinct? No. You should have talking points prepared. But OP is mostly on the nose. This sort of demand for conclusion sans explanation only to go back over what you would’ve explained anyways is usually driven by external stress.
Time management ia important when your time is highly valuable with opportunity cost.
This isn’t unique to business...academic papers have abstracts that do this; math proofs have the statement they’re proving up-front.
"Results may wary"
This is one of those things I've discovered has no right answer. Some people will appreciate you getting to the point first, and others will hate it. Sometimes it will save time, other times it makes things more protracted.
And some people are prone to dismiss the conclusion without hearing the rationale. Definitely don't start with the conclusion when discussing with them.
Whether the conversation is live vs asynchronous also makes a significant difference in this.