New navy units Battleship and Dreadnought proposed

Why is there no Battleship and Dreadnought ships available? You can have Destroyers, Aircraft Carrier, Helicopter Carrier, Frigate and Guided Missle Cruise ship.
Can Battleship and Dreadnought units be created for the navy.

Modern navies are phasing out cruisers. They're basically obsolete now. The US Navy still have a few but I don't think they build them anymore.

I would imagine that big capital ships in the modern age would be very vulnerable to anti-ship missile systems. I am no expert on this, but I believe most modern navies now use aircraft carriers, missile destroyers, and submarines.

But on this game they could add them

It's an anachronism, Josh. It's like having chariots or siege engines.