[Suicide Junkie]

Nothing in SE5 makes them more useful.

It is the mod.
The general idea is that maintenance costs are fairly flat rate, but build costs go up proportional to the square of the ship size.

You can build 30 frigates in the time it takes to build one dread, but those frigates have most of their space devoted to a single 60mm Laser...
A battleship big enough to carry a 100mm gun and still be well armored is scary. Mmm. Those Yamato class Battleships in the FTP game with Sivran were sweet and scary. Ripped destroyers in half with its main gun (100mm Laser), and chewed up the remains with its secondary batteries of 80mm DUC.

(Weapon size/damage is proportional to the square of the bore diameter)