Have you ever used a headlamp? I have one sitting in my junk box. It was used for precisely one night dive and it had to be one of the most nauseous experiences I ever had. It attracted every creepy crawly small creature around and they covered my mask, crawled under my hood and into my ears.....
Even before it attracted the swarms, the backscatter caused by having the light close to my eyes ruined the vis.
So it really depends where you dive.
Nowadays when I want hands-free I use a glove support for my light. The light is mounted on the back of my hand.
Head lights are also a pain for buddies when you inadvertently look at them and dazzle them.