This is the same dialectical "right" vs. "left" rubbish that means nothing considering both parties are, in fact, wings of the same doe doe bird....
While there is some truth to this statement, I think it's erroneous to think that there isn't a difference between Democrats and Republicans or that the difference between 'right' and 'left' is merely rubbish.
Certainly, the two parties are part of the same system or 'doe doe bird', as you put it. And it would be foolish to deny that the phony conservatives, so prevalent in the Republican party today, have blurred the differentiation with the Dems. But at the same time, it's also inaccurate to think there isn't a meaningful difference between the parties or the candidates and the policies they offer.
Your cynicism is understandable, but your conclusion isn't entirely accurate.