From an economics standpoint, the poor get poorer and the rich get richer.
Credits as the player uses them are likely galactic credit that are exchanged to a much larger amount of planetary credits.
Most of the weapons in Starsector don't actually make sense in terms of space combat. Two fleets would be duking it out from the distance from the Earth to the Moon, not close orbital ranges, and the only weapons that make sense at those ranges are beams, missiles, and hangar units. Ballistics would be purely PD. Worse, if we're going for realism, every non-beam weapon should be subject to PD since their trajectories can be calculated in less than a second, and it should take them a very long time to reach their target, realistically speaking.
https://youtu.be/ovAiAlGGQusFor realism we have ships coming in, firing off Anime levels of missiles, shooting down enemy missiles, shooting lasers at each other, and massed hangar units dominating the skies. Between the fleets is a no-man's land of hangar units and missiles crisscrossed with lasers. Offensive ballistics would be the god weapons at close range that pierce through entire ships and run down a column of ships dealing massive damage.
So, Starsector doesn't make realistic sense. It doesn't need to. It is a game. The design of how combat and trading works has evolved to be more fun to play.
Oddly enough, you can do something that is an approximation of realism with Mora mono-fleets. They're insanely deadly. I've tried them with massed reapers. I just tested them with massed Pila, and they're taking down 5 star remnant fleets more easily than with torpedoes.
Turns out Medley Moras using massed Pila are potentially the apex of moras when massed. Not sure how well it works with Bombers, though.