Both exist tbh. My more medicinal shampoos smell of nothing or bad (assuming because of the active contents and not to smell more medicinal). Sensitive shampoo/detergents seem to be very lightly scented. Kinda just enough to where you can check if your kid washed their hands by smelling them but it doesn't release a citrus bomb around the sink.
The scent thing can be useful for a forgetful person wondering "did I wash my hands recently?"
Lots of products smell bad if they're truly unscented. "Unscented" is an effect that is often achieved with... scent. So, still putting stuff in the air for you to smell, but to counter other odors so it smells neutral to you.