You seem to be speaking from your hotel’s point of view. I guess your hotel never gives more than a 10% discount, either online or in-person?
Other hotels, also hotels of quality, give much deeper discounts. I routinely get 30-40% discounts using Expedia. If I called up, there is no way I would get a discount that’s anything close to what Expedia gets me.
You say you’d never book online? I will never book in-person.