Because it was clearly known to the artist. This comic doesn't even make sense unless you know both the original and that these are Elden Ring characters.
So it's not well known enough to be parody as opposed to plagiarism in one context, but everyone has heard of it and is calling it out for plagiarism in another?
I can follow a conversation just fine. In one thread, someone says it's more parody than plagiarism, although the original isn't super well known so people might not recognize it as parody, to which you reply that it obviously is since three people have called it out for being plagiarism. In this thread, you ask how something can possibly be parody if the original isn't well enough known.
Funny though that you gripe about a comic not being well known enough to be effectively parodied in reply to a comment saying the original has its own KnowYourMeme page, then accuse me of not being able to follow a conversation.