Booking.com takes an 18% commission. Only a severely incompetent business would refuse to give you a lower price in exchange for them not having to pay that 18%.
All the big franchises (Marriott, Hilton, IHG, Hyatt, Choice, Wyndham) will give you a cheaper “member” price at their direct website. Being a member is free, it’s just like airline miles and you even earn points.