The question is not how a succubus tastes like but why you would eat one.
1.If you kill a succubus you have to destroy her whole,the protag kills each one with fire so there isnt anything left to eat.
2. As someone said above it is very possible it would be harmful or even lethal to eat one,if not the physical properties of the body then the demonic energy in them,I wouldnt put it behind them to possess a human that eats them or make him to arouse/corrupted that he turns into a demon or willingly seeks a succubus to be drained by.
3.If eating succubus was possible then most likely humans would do that in-universe like the warlike tribesmen but we dont see that and enough time has passed.
All in all i feel this is a redundant question such as the fanstupid one "can i have sex with a succubus but not kill me?" or "can a succubus be pregnant?" ffs like the lore doesnt say this already.
I would like personally to see more human enemies like the witch that made pacts with the demons or newly corrupted women,this would make it more dynamic and interesting to face such unique enemies.
