It is literally impossible to know or to tell, isn’t it 
So I can act as this means my experiences are entirely arbitrary or that the consistency they have is indicative of an objective truth beyond my self. Obviously the whole thing can be a construct entirely of my own making, who is to tell?
However, my experiences have shown me that treating reality as a construct has severe negative effects on my ability to function. I’m not talking about doing random things because I don’t think consequences are real, but rather, mentally untethering myself from my sensory inputs causes me problems. Even if objective truth is not a thing, that would still hold true and I like to try and enjoy my experiences rather than be damaged by them.
Honestly I’m a fence sitter but literally the only person benefited or disadvantaged by me choosing to believe or not in objective truth is me. I’ve spent too long in my life pondering unknowables and I’m going to regret some of that time on my death bed, so I’m going to do what makes me happy.