I think we sort of have to assume in this “What if” question that the king is unquestionably wise and has the capacity to take care of us..Practicalities such as “how do we know he really is benign” or “how do we ensure his or her successor is also wise” are outside this question.
I think though, one of the problems with the philosopher king is that having someone “take care” of us can lead to the citizens becoming like sheep.
Citizen participation is good for the citizens. Participation cultivates a sense of responsibility and dialogue, which is important for the community. We shouldn’t just allow one person “take care of us”—not necessarily because of a checks and balance things (because in this hypothetical, there is no need for checks and balances), but because it is healthy for us to participate and thinking, caring citizens.
I assume that the philosopher-king would be smart enough to see that.
But in any case, if it was a benign dictatorship, my personal acceptance of the king would be largely irrelevant.