Most of us have done some form of study that involves a section on improving communications.
We learn about the importance of making any message appropriate to the target audience - using the right language, using appropriate images, and so on.
We also learn about choosing the medium for the message according to factors such as the need for speed, the need for feedback loops, etc.
Yes, it is neither of these that is the main factor in determining the effectiveness of communication.
What matters most is the desire to communicate. Does the sender of the message really want to communicate - clearly - to achieve his/her desired results…. or is the communication process a ‘box-ticking’ exercise.
Where there’s a will, there’s communication.
Where there isn’t, there is much more likely to be confusion and misunderstanding.