Here's an example of some dialogue from Underrail, one of the best indie RPGs to come out recently and much adored here on the Codex (rightly so I might add)
I guarantee most of those responses, hell maybe all of them, have zero actual consequences (if there are any, the wiki doesn't mention them).
But this moment is still important because it gives the player a chance to decide how their character will respond. This is just one way that RPGs immerse players in their game, not every piece of dialogue has to have consequences. I personally was tempted to pick response 8, but I decided to say nothing instead since I figured it was a waste of time to cause a ruckus, and I was sort of worried that I might get thrown out of the city or something like that.
Tell me more about how dialogue with no consequences is 'irrelevant' though.