On a personal note, I keep wanting to call this an isekai series, even though it's technically not. I consume a lot of media from East Asia, and so find myself defaulting to their terms for various (sub-)genres. While LitRPG and isekai are technically different (in that the former has the characters being aware of, and interacting with, various RPG statistics that govern themselves and other beings, while the latter means that the story begins with the protagonist being taken from their home world, typically Earth, to another), there's a lot of overlap in that particular Venn diagram.
I don't know why I felt that was important to establish, but given that I just wrote a paragraph about it, I apparently felt very strongly that it was.
My suspicion is that it has something to do with how both genres make heavy use of a particular set of tropes, which are quite often the same tropes. Incidentally, this is quite often the point on which these stories tend to be criticized, which is something I'm sympathetic toward. I think that originality is overrated, in terms of what's important for making a good story; execution matters much more.