A few highlights that I'd like to make about this tool and its usage. Note: on a prescriptive level I'm focusing on moral matters, not legal ones.
This tool allows you to edit your content. You might have allowed other people and Reddit Inc. to use it, but it's still yours. And you should be free to do whatever you want with your content, even if it inconveniences others. And people expecting you to give up your moral rights for the sake of their own benefit, frankly, are simply entitled.
Another user here compared this with vandalism; I don't think that the comparison is good, given that vandalism targets someone else's property.
I also think that people in general are focusing too much on the short-term consequences of the usage of this tool, and too little on the long-term. Here comes some bullet points hell:
- SEO "improvements" already caught up with the "add «reddit» to search queries!" trick. It's becoming less effective over time.
- Reddit is accumulating huge amounts of noise, due to increased bot activity and decreased moderation. It'll likely get worse over time.
- Reddit is walling itself off more and more over time. Eventually this info will become unavailable for anyone who
didn't sell their soul to Greedy Pigboy isn't feeding that cesspool. - Every piece of content that you leave in that site is yet another piece of content "inviting" other users to register and stay there, dumping their content into that increasingly walled garden, where it won't be available publicly. And while they're free to do so if they so desire (it's their content), you're also free to not invite them.
- There are alternatives to that enshittified platform, competing directly with it. (We're in one, by the way.) We should encourage people to use those alternatives, not Reddit.
Are you all getting the picture? You might be tempted to leave your content in Reddit for the sake of other people; even then, the pros of doing so are rather small, and there are cons not often mentioned.
Regarding LLMs, frankly? I think that it's mostly a neutral point. Sure, data hoarding bots will get your content from Reddit... but they'll do it if you post here in the Fediverse, in your blog, or elsewhere. The only alternative to not feeding those bots is to not speak "in the open".