The power needed to produce lift in a hover is determined almost purely by the disk loading (the weight of the aircraft divided by the area of the rotor or lift fan nozzel).
For a helicopter, about 5 to 10 pounds of weight are lifted by each square foot of rotor, for a tiltrotor it is 15 to 25 pounds per square foot, and for a vectored thrust, it is about 1000 pounds per square foot. This makes tilt rotors need about 45% more power than helicopters for the same total gross weight, and vectored thrust machines consume about 100 times more power that a helicopter!
This power efficiency for the helicopter means that they burn less fuel in a hover, carry more payload, make less noise and cost less (since it is the machinery that makes and transmits the power that drives the cost of the machine).
The advocates for non-helicopter configurations always mention the advantages (speed, especially) but often never quite get around to mentioning the significant cost of that speed in terms of reduced payload, purchase price and maintenance burden.