Why is such a simple statement so unusual? Because the human race is not engaged in the search for truth. It prefers to live a lie.
People in the West are not supposed to say such things. And if they do, it tends to cause a defensive reaction of reservation and resentment in the hearer, largely because of shame that someone else (and not yourself) has dared to go against common ignorance and been bold enough to declare the fruits of it.
Many men and women endeavour to create the impression that they know the truth. But because they do not know, they are very careful not to declare and expose themselves.
There are also persons who do not know the truth but who present it to you by quoting authorities outside themselves, usually masters who are safely dead. This tragically perpetuates the fiction that the individual man or woman - you - cannot know the truth in your own right. I know the truth. I do not need to quote others. Therefore all men and women can know the truth with the same certainty and directness.
In fact I think it is the opposite of what you say, there are far too many claiming to know the truth and they say it very loudly.
I am not a robot. Click on street signs.