Imagine, someone became so good at lucid dreaming that he/she would be lucid through his/her entire sleep, would it be harmful to the reason that each day we sleep: Resting/ recovering/ Reload our energy... ?

It's not that I'm worried that it might but whenever I tell someone they tell me that anybody that lucid dreams is gonna go pshyco after a while because if they're conscious during their sleep, they are not resting, therefore they will be tired at all time, go crazy or all the rest that happens to people who do not sleep. When they tell me that, I don't know what to say to prove that its not true. The only thing I find to say is:

You're body is what needs to rest and even if your lucid, its still resting so it doesn't matter.

And then they say: "Your mind has to rest too"

And my answer is: "The way your mind rests is by dreaming. When your lucid, you're still dreaming, so your mind is still resting."

I actually just guessed that. It was the most logical answer that came to my mind (no pun intented). I wanted to know if there's a more "scientifical" explanation to this. (Or if, it actually stops you from resting)

Thanks