That's the point, people suffer because we're too coward to communicate, even thou the solution is usually that simple.
By making the solution to so many complex things this simple, you're encouraging your readers to do the same, that is all.
Sure, but none of that changes the fact that the writing and the execution is shoddy. Communication being hard and complex is not a novel idea, it's basically the lynchpin to any proper drama. And given this is a manga, and not Chicken Soup or an inspirational column, how the story executes and writes the main motif or message is more imp than the supposed "moral of thestory".
If this happened a couple of volumes ago, it'd make more sense. If there was more buildup and focus on the character's feelings and motivations that led to the recent "impasse", it'd feel better. If we didn't abruptly break off from their cosplay becoming an internet sensation to this drama focused arc, I wouldn't call the writing shoddy.
Anyway, as i said in another thread, author is bad at drama. Series always worked best in slice of life, or some lower key drama