The impossibility of separating facts from guesses is exploited by people whose aim is not to solve the problem, but to gain some benefit for themselves, such as winning support in parliamentary elections, selling some product, lobbying in somebody’s interest, or simply shining in public discourse.
By treating their opponents’ arguments as opinions, even though they are facts, they deprive them of their strongest asset, namely the unambiguity of reality.
In a situation where no one can distinguish what is a fact and what is an opinion, and facts and opinions become intertwined, everything turns into mere opinion and there are no facts left. Reality becomes ambiguous, because everyone may have a different opinion about it, and then it is impossible to see where the truth lies. The logical correctness of arguments loses importance, and the most important thing becomes the persuasive force of the spoken words.