Can my question:
be unmarked as a duplicate?
It has nothing to do with:
The latter deals with the Sith code of ethics, and the strong ignoring the weak, and effectively asks "why would one Sith help another, junior Sith". It is an interesting question.
My question asks why Palpatine bothered with Vader, given both Vader's uselessness to the overall story arc (aside from killing Palpatine) and Palpatine's ability to see the future. It also (implicitly) inquires why Palpatine, who is solely responsible for everything that happens in the prequels, even bothered with an apprentice at all.
The questions are different, and while they're both good questions, that's not a reason to mark them as duplicates.