Both Marx (and Engels by extension) and Lenin were extraordinarily important in developing a revolutionary worldview. It’s important to preserve their names as they are both an unavoidable source of knowledge. Removing one or the other completely scars both. Just so you see how this is important, there are a lot of Marxists who ignore Engels’ contribution, I’d say simply because Marx is more known than Engels, and thus, more prone to be read. The fact that our science is called “Marxism” undoubtedly has contributed to this. So preserving Marxism-Leninism is important to not diminish the contributions of one or the other.
This paragraph alone would have been enough to answer OP’s question.
I don’t understand why such an innocent question can generate so much hostility, we’re all here to share and to learn.
I watched The Substance yesterday. It’s not really scary, but it’s very disturbing.