On the contrary, I think it's more interesting to have the countries themselves undergo their own "character growth".
There's been conflict with the Garlean Empire at the center of the game's setting for the better part of a century and for the period of the whole game's existence for us players. In almost any other setting and even with experiences in our own world last century, the Garleans having been brought to nothing mostly by their own hand and at the mercy of their victims would have no "right" to self-determination and be split up by their enemy and bits portioned out as war reparations. Instead, the Eorzean Alliance says they need to rebuild themselves without international oversight. The leaders of Eorzea realize the world is not some zero-sum game where you need to take from your neighbors and make everyone your country in order to prosper and be safe, and international cooperation builds everyone up together. Now the Garleans need to pick themselves up out of the ruins and build their country back up while having to navigate that world while managing the ruins of their country and a regime change and it will be interesting to see where they go from there. If SE decides to even continue that storyline...
Some other countries have already gone through lighter versions of this.
Limsa Lominsa in 1.0 was solely a pirate nation and a parasite in Eorzea until Merlwyb took over and they're still going through growing pains. Merlwyb rules with might as a benevolent dictator supported by her old worst enemies, but that could change at the next Trident unless she makes herself dictator-for-life.
Ul'dah's monarch herself tried to establish a regime change on her own volition, but ended up being used to remove someone else's political enemies and secure Monetarist rule. That showed that even the best intentions can fall flat and democratization can fail in this setting. The city-state is still ruled by those with their own self-interests in mind ahead of those of Eorzea as a whole.
The ruling class and the church in Ishgard ruled based on a lie to keep up a forever war and with the war gone and the lie revealed, the rulers had no ability to control the armed and angry majority. Ishgard could have ended up a lot worse with a guillotine in the Hoplon.
Ala Mhigo had to build itself back up after being occupied for 20 years and a civil war against the previous royal before that. With the entire ruling family dead except for 1 guy who wants nothing to do with it, what did you expect to happen?
Doma on the other hand kept its monarchy because the previous royal family was benevolent, well-liked and supported, and more importantly has someone from the royal family who is still alive and willing to rule.
All that in mind, it does not make much sense to me for the surviving populace of Garlemald to decide to nominate an emperor considering they had 2 civil wars that completely destroyed the city and brought the country to ruins over whose royal butt is going to kiss the throne.
Not everything has gone the Scions' way and it's been a lot of effort to get to where we're at even now. Not all countries, even the main 3, are democratic. There are still different ideas on how to rule, but the majority of the known countries are now allied due to necessity in order to survive the empire, so now their thoughts more or less align and they're friendly with each other. It also makes sense to change your government when your old one ends up getting wiped out with no one specified to replace them. Especially so when the old government killed their own citizens and in one case brainwashed them and fed them to each other. No need to use Alphinaud as a scapegoat, as much as I don't like him.