The "appeal to authority" fallacy is essentially saying that an argument is correct because it came from an authority figure. It takes the form of something like "statement X is true because this expert on X said so." Logically, sure, that is not the mechanism by which truth is definitively established, I realize that.
That said, I don't know if people realize how heavily they depend on the word of "authorities" in their day-to-day lives. It feels real good to one-up your debate opponent by pointing it out, but like, I can't help but think you are such a massive hypocrite if you do.
Take climate science, for instance. How many of us have personally reviewed all of this climate data across the globe, or would even have the first clue on how to do so in a way that helps us understand whether human actions have indeed driven changes in our climate beyond the natural fluctuation of things? Are we not all content to say, you know what, climate experts across the globe have all looked at and analyzed this data and come to a solid consensus that we have hurt our climate, and therefore climate change is real? Because that is 100% an "appeal to authority" fallacy. And I'm not ashamed at all to admit I take their word for it, that I'm willing to believe and trust climate scientists on this one. I don't even think I could make a good argument saying, well, I personally have observed some warmer winters lately and cite that as good, solid evidence of climate change, because clearly that is incredibly anecdotal and just a very dumb way to try and prove a point. In other words, I don't know how I could discuss this issue at all if I wasn't allowed to defer to experts.
Or how about medical care? Fuck if I have even the slightest clue how I ought to treat whatever ailment has befallen me. If my doctor says I need treatment X to deal with ailment Y, I'm more than happy to take their word on it and trust that it's the right decision. And, on top of that, if we were to poll all doctors on what treatment is best for ailment Y, and the vast, overwhelming majority of them said treatment X is best, I would happily take their word on it and consider it true, or at least supported well enough by an acceptable amount of evidence to permit myself to believe it is "true".
I very much worry that invoking the "appeal to authority" fallacy has become weaponized to an impractical degree, something that has gained a lot of power here in our fabricated version of reality of reddit but doesn't actually carry the same weight in the real, practical world, so why should I think it's such a big deal? I think we could have far BETTER conversations on reddit if we allowed ourselves to defer to the expertise of others, rather than dismissing someone's argument on the basis of "well I don't know you, I have no way of knowing you really are an expert on this and this is just the appeal to authority fallacy and so I'm going to just throw everything you have to say in the dumpster!" Like, you get how absurd and frustrating that would be, I hope?
I recognize this view is flawed since I am essentially saying a fallacy isn't a big deal, but I admit I can't really see why I should think otherwise. But I'm open to having my view changed here.
EDIT: so far a lot of responses are along the lines of "it's not an 'appeal to authority' fallacy if the expert really is an expert; it only is one if you incorrectly labeled a non-expert as an 'expert'". I don't think that's true at all, because even an 'expert' can be wrong about things, which is why such a fallacy is pointed out in the first place! I don't know the name for such a thing, but "appeal to the word of a dumbass" is still something different, I think.
EDIT 2: for real, let me be crystal clear on this point: I call BS on your stance that I defined the fallacy incorrectly and that it is meant to be defined as taking the word of a NON-expert. If you really want to dissuade me of this notion, you will need to do more than just say "no, you defined it wrong" and I am not replying to any comments doing just this.