we each and all are incapable of knowing the absolute factual reality
There you have it, Truth and reality are different sides of a coin. Man can't see the truth. We can only have a perception of what we might think it is.
Just by claiming that truth is relative we could cause harm to our society if everyone has a truth, automatically everyone is right, therefore concepts such as good or evil would be extremely relative.
There are universal concepts that goes beyond human understanding.
2 + 2 = 4, that's truth.
Gravity is truth.
We cannot claim to know the absolute truth, and thus must, if we are honest, acknowledge that other's truths are necessarily different than ours.
Yes, you are right, but we could try to reach it we must follow towards the absolute truth because it is there and we know because of the Facts that absolute truth is real. If facts wouldn't exist, the absolute truth wouldn't exist too. Facts are the tools we use to ascertain that truth exists and we can reach it somehow.