Nothing says power like a carrier battle group. This is part and parcel of the gunboat diplomacy that gave the US its status in the world. There are far too many interests to protect and too few cruisers. Subs cannot protect lanes, they need to be visible.
As for BOTG, we go when/where we are needed and we need the ability to sustain combat ops for a minimum of 30 days (MEU) or 180 days (MEF). ARGs are the only way to accomplish this.
Nothing says power like dropping a JDAM on someones house, ask Khaddafy and Reagan.
You can keep your ARGs, but as technology improves, all they will be is a target rich environment for the other sides drone attack with a one shot railgun round right through the ship at the water line.
Submarines can hide and sink whatever needs to be sunk, and a few good cruisers will fly the flag.
The real threat is bombing the house of the leader. Everybody else stands down when you do that.