So why did he have to sleep in a crystal for? What was the purpose of the empire/Teneabre if they just blew them up off screen? What was Luna's actual purpose? Why was all the development for Gladio, Prompto and Ignis in side stories? In fact, why did gladio just up and be like "oh i forgot i had something to do" when they were on the most important mission of their lives? Why is all of the villian's development in side stories?
Its not even a good game breh. "Special Edition" or not. That whole "it'll be better in 8 months when all the DLC is out" is a trash development style.
He had to sleep in the crystal to absorb it's power so he could purge the daemons.
The empire found Adyrn in the same island noctis and he help them create their army of daemons to get revenge on the line of Lucis for stealing his throne. Tenebrae was annexed by the Empire, they ran out of time to finish the game that's why you can't explore Tenebrae. If the development was in the main game, you wouldn't need side stories, they did it to sell DLCs.
Gladio got manhandled by Luna's brother in a confrontation and realized he needed to get stronger in order to properly be king's shield so he went off to take the trail, that's clearly explained in game without DLC, that he was questioning his ability to protect noctis, the DLC shows the trail he did in order to get Gilgamesh's power.
Aryden was well developed, the side story just shows the events that were explained in the main game already, plus it is the side story to sell DLC
Final Fantasy XV story is straight forward, its call back to the orginal NES games which were simple, where the warrior of light went on quest for the crystal.
Final Fantasy VII has more more plot holes, you have to do certain things to trigger cutscenes that explain the story and you can mess them completely and still beat the game not knowing zack's back story, vincient or who Sephiroth's father is etc
Each character had development in the main game
Gladio not respecting Noctis, they arguments during the titan fight
and on the train after ignis got blinded, then when Noctis finally has to get put the ring, he earns Gladio's respect.
Prompto felt like he was a weak link in the party and not really apart of the team, he was created by the scientist in empire and was suppose to be a magitek shoulder, and had to come to terms with that.
Ignis went blind, because had to put on the ring to save Noctis' life, which added to the beef Gladio had with Noctis, because Noctis still wouldn't put the ring on because he was afraid, yet Ignis did it without hesitation and went blind because of it.