>>17834598 (OP)because a lot of civil wars gradually tend to be between centralizing vs decentralizing forces
if the centralizing force wins, much of the decentralizing forces are removed, making way for greater centralization, ie, override and overrule of the provinces that allow the state to be stronger.
if the decentralizing forces win, there's greater autonomy to the nobles/aristocrats/provinces away from the central authority, which usually weakens the state, or leaves it at prey to external factors
If you have a civil war between forces for different methods of centralization, it's all just about the political method and application, usually as a method of replacing a present system that is viewed as inefficient or insufficient. It gives a chance for a whole new set of reforms, radical or otherwise, to be put into place, in attempts to change the systems, for better or worse. The fact that it was done by war and not by some peaceful transition usually means there's good odds that a purge/mass exile/cabinet stacking can remove members of the old regime in order to gather support force/force through the new changes, preventing any lingering, retarding factors that might've existed in the previous administration
Of course, there can just be purely ambitious forces in a civil war who just want to seize power for themselves and them do fuckall with it and make more problems for another civil war, but they can sometimes gather power amongst themselves for some level of stabilization. Centralization can also turn into hedonism and nepotism, as absolute power can corrupt, which then leads to an inefficient or insufficient system; this cycle, if perpetuated, does little to benefit a country because long-term stability is needed for centralization to take time and effect, and can also lead to decentralizing forces due to the failures of what a centralizing power can look like