why do we need bases in discovery?
why do we need bombers in discovery?
why do we need caps in discovery?
why do we need so many other things that are non-vanilla?
because they enhance the game environment, while i dont think bases ever enhanced anything the other stuff did certainly.
also it greatly depends on the size of your carrier and the need it was designed to fill, as to whether carriers need to exist.
the 75th carrier houses all the ships of the faction and provides home for all involved, i.e is of critical importance. from a gameplay viewpoint could do without it, as will many other things as stated.
if your carrier is small enough to be cheap to build but large enough to house a lot of fighter craft, then it is absolutely a good addition to a fleet, specifically for offensive movements, you are also thinking of space as large as it is in freelancer, humans get tired, they need to rest, if you are away from home you cant just nip home for some fish and chips in 10 minutes like you can in the game.
also "the vanilla battelships were carriers" no, no they were not. being able to hold 1 or 2 fighters does not make them a carrier, even some WW2 ships had planes suspended on cranes in their rigging to launch whenver needed. are they carriers now? no.
Carriers should fill the role of carrying fighters and protecting them, while providing a place for the pilots to rest before their next mission. and since you dont need a huge runway youd be able to build a much smaller carrier than current existing ones, which would drastically reduce the cost required, making them a better buy than a battleship, however carriers should not be able to go toe to toe for these reasons.