From a development standpoint, if we made a bigger capital ship the very first thing a modder is going to do is say "I bet I can make a bigger one!" - which, of course, is totally cool for modders to do and it's always fun seeing ridiculously crazy things being done.
I don't think our efforts on vanilla Starsector would gain anything from engaging in a ship size arms race but rather making the world deeper and more interesting to give the ships that exist more meaning so their 'narrative size', if you will, to grow. Like, I'm interested in where the Buffalo class hull comes from, what's it's used for, what every faction does with it, and what that means to the future of the Sector and how that interacts with the player's perception of all of the above.
(Also from an artistic direction standpoint, the biggest capital ships are the size they are to be reasonably sized sprites at the default zoom range on relatively modest monitors, and to work reasonably with the existing 2D armour/damage/weapon range mechanics.)
