When someone makes a bad-faith argument, should one go to great lengths to refute it? Perhaps sometimes. Other times, it is better to dismiss it as nonsense and get on with one's day.

"Trickle-down economics" is an extremely bad-faith argument, essentially boiling down to "rich people pay slightly less rich people to tell poor people it's better for The Economy if they stay poor". That it was ever given credence in the first place reflects very badly on the economics profession (or, as I would reframe it, shows that economics as a subject has been wholly captured by elites).