With how stingy the rewards are, combat has to be easy or else the player loses money (replacing lost ships). That 250k+ bounty (which has several enemy capitals) does not even cover the cost of a new capital. Smaller bounties too for smaller ships. I consider loot they drop roughly covering the cost of travel and repairs. I would prefer the game to be balanced around player losing ships, but rewards need to be much higher to cover the cost of replacements. Thus, combat with the current rewards needs to be balanced around flawless victories or close to it. However, when the game is balanced around flawless victories, the game looks too easy. The challenge then is not whether your fleet survives a total wipeout, but not to lose any ships so that you have a decisive victory and make profit and progress, not a pyrrhic victory where you are effectively defeated and are set back enough that it is faster to reload the game and replay than to continue and recover from your losses.
With the investment colonies need, they only start printing significant money after they reach size 6 when they no longer need hazard pay. Before then, they are a money pit (for all of the buildings paid for). Whatever meager profit they generate is gobbled up by fleet expenses and/or further colony buildings (or a new capital for the fleet). Once player has five size 6 colonies, he can make close to a half a million per month, with only minimal items and without any AI cores or colony improvements. Once extra items and improvements come in, income from those five worlds can be pushed closer to a million per month. By then the player starts getting a return on the multi-year investment (i.e., printing money), and the game is effectively over. I usually get my endgame fleet before I get my five size 6 worlds. I am not printing money when I have the ships to fight Ordos because the colonies are still growing.
P.S. As for pacing, the enemy scales up faster than the player. If the player gains power too quickly, the enemy gains power even faster. Player needs to play catchup with the enemy. Bounties scale way too fast. Old releases years ago had better pacing for the enemy.
I do not think the player gains power too quickly. I do not have time to play Starsector hours on end anymore, and I like to reach late game as quickly as possible. Early game, or pre-colony part of the game, is the part I like least, and I like to get it over with as quickly as possible. In newer releases (probably since v0.9a), I play only one or two games per release (depending on how many hotfixes Alex puts out after release) because of time. I have no interest slogging through early game by restarting the game. I want my ships and weapons, and I rather keep one good game (save) handy at all times and stick with it. I do not want to replay a new game because it takes too long.
P.P.S. Thanks to crises, I need close to an endgame fleet to fight the major factions if I want their rewards. Some peaceful options deny you rewards or steal/drain colony income, so of course combat is the only option, except for pirates (and maybe Church with their sabotaged world takeover exploit). That means I need my endgame fleet when my colonies are still at size 4 or 5, long before they are printing enough money to make up for the costs sunk into colonies.