Try this thought experiment. Imagine that every single one of your posts here disappeared, tomorrow. You with me? Now, what would happen? How would your life change? How would this forum change? How would "the public" change?
Are we talking "never existed" or just got deleted, because these are two entirely different situations with completely different outcomes!
For me the main benefit of discussing stuff, including arguing, at this point in my life, is two-fold:
1) I often sharpen up my own ideas and even become aware of what I really think about stuff in the process. This has actually been pretty beneficial to me overall.
2) I learn things. All sort of things. Often interrogating people (in the most literal sense, not tying them to chair lol) about stuff can be highly informative, and can bring out unexpected stuff.
For me, sometimes you have to point out logical flaws and so on in order to move forwards. I've seen this very clearly within the last two years. There was a thread here with an interesting discussion, but one poster had a serious logical flaw "stuck in their throat" as it were, and was basically spamming the thread because they couldn't get it out, and kept repeating stuff. Eventually they were made to understand the flaw, and the discussion progressed, and was more interesting.
But to come back to 1, if I'd never argued with people about stuff, I'm absolutely convinced I'd be the worst for it. My ideas would be the worse for it. I don't buy this "pigs" analogy, because I'm not arguing with pigs - i.e. real trash like Nazis - I'm arguing with fellow human beings, most of whom aren't terrible, and many of whom I can learn from.
One nice thing about this forum, too, in this era at least, is that it's less "factional" than many, in that I may end up agreeing with someone one day and disagreeing the next, which means I'm more attentive to what people are actually saying and learn more from discussions.
Also just as general point, I've sometimes come across old arguments, read them, and been convinced by them, before I've even posted about something, often changing my opinion. That's something I like about forums.
As for:
There's a reason that everyone (EVERYONE) knows the xkcd comic ... THERE'S SOMEONE WRONG ON THE INTERNET. We've all been there. That rush of putting someone in their place. Of knowing you totally pwned him. Of feeling the exhilaration of making sure that "the public" wouldn't misunderstand the argument.
Yeah, I mean, who hasn't fallen into that trap? I did a few days ago. People misunderstood a mechanic in Total War Warhammer 2, and were dismissing a problem as a result, and I felt the need, not to "pwn" anyone in that case, but to explain stuff over and over for like 40 minutes before I said "That's enough of that!" lol.
But I've often had a lot of positive feedback on this kind of stuff. Like people thanking me even. And then in some places seeing arguments I made repeated (sometimes almost word-for-word) as the right approach later on. So I don't think it's as worthless as you're implying, given I'm just one human in 7+ bn, and thus arguably we're all of limited, dust-like value.
The trap is not knowing when to stop, which I suspect you agree on. When I was younger I definitely didn't know that.
You should branch out from the Roman material; ethos, pathos, and logos are straight-up Aristotle regardless of any later appropriation by Cicero. However, if you truly care about argument and winning, you should note that people are not logic machines. If you want to appeal to people and convince them of the rightness of you cause/argument, you don't do so by logos alone.
Yeah I guess I myself am trapped in a potentially stoic-like mindset where I don't really
want to win an argument that I'm not sure is logical, like I'd honestly rather lose and be convinced by the actual logic (which has happened, countless times - I know people
say no-one changes their mind, but I also know that's utterly false, from both lived experience and seeing others do it). So at a minimum the logic has to be there lol, for me, anyway. Not going to talk politics but I feel like in the world today, especially in my country, there's an awful lot of people winning arguments with a ton of pathos and very little logos and limited or false ethos. Maybe that itself is a lesson of a kind, though?