I hardly see how posting a meme that was already posted there is making Lemmy a copy of Reddit. Do you think that most memes you see here are OC?
Edit: on further thought, even if communities end up with a lot of "copied" posts, why would that be bad? I don't want to go on Reddit to comment on it. I am not even aware it was posted on reddit because I have not opened that domain in years if not by web search. Users are what make communities more than the posts themselves, so if someone wants to share something for any reason, I don't care if it came from reddit. I don't care if it came from 4chan. I am here to engage with the contents of the post, its poster, and the rest of this community. This kind of meta-discussion about what other servers this collection of bytes has been on previously is pointless at best, and empty virtue signaling at worst.