No one will remember who won an argument on the internet, they'll just remember that everyone involved is the kind of person who gets in arguments on the internet.
I'm not even sure that's really limited to just the internet either - outside of very niche cases, you don't win any argument, you just become known as someone who likes to argue, and thus you need to decide if this is a venue you want to become known as someone who argues about things. There's venues that may be good, wholesome, and useful, but it's been an axiom that's definitely stopped me from contributing to a lot of arguments.
The problem with discussions on the internet is that there's a lot of ignorance and ideology out there and a lack of interest in applying a modicum of thought, research and critical thinking. People know what they know because they know what they know, and that's the end of it. This can be incredibly frustrating to those of us who make an attempt to live in some kind of an objective realty, where arguments from reason and facts are considered and respected.
On the internet, the earth can be flat and there is no amount of math and science you can deploy that will convince a certain audience otherwise.
The only exception to this rule are narrowly focused professional discussion groups. HN fits this description ONLY when the topic at hand tends to be in the realm of specific engineering disciplines. In a wide range of other areas, including technical areas, discussions on HN can be just as dumb and pointless as almost anywhere else.
I've been using online forums of various kinds of four decades. You could find good, bad and ugly on USENET and the same is true today in various forms. The only thing that has changed is that the size of the audience and the reach of the nonsense have expanded.
Relevant:
https://www.cnbc.com/2023/01/19/yale-researchers-how-highly-...
What you neglect totally are these:
1. this can be fact of arguments anywhere, and the key to having a decent one is for all members to act in good faith
2. the internet affords the ability to find sources quickly and quote them, unlike non-internet (especially before smart phones) where it is 'who can say things most convincingly or plead to already existing biases' (which of course does happen, but at least opposition has a chance)
3. on the internet you are not arguing with one person, you are holding a public debate which is forever etched into history for anyone to read
And, yes, in real life you better know what you are talking about. You can’t google yourself out of it, particularly in professional settings.
My statement is more that if you're interested in external impact, exposing someone to a new idea should be treated as the most likely outcome, so assess your effort spent accordingly. I've gotten a lot of value out of reading the different sides of other people's arguments, but I know I personally wouldn't have wanted to spend time being part of it.