PoE2 needed to have a tighter focus on the narrative, I feel. The main quest could have used a couple more steps, I think it moved far too quickly, which didn't give the companions enough time to develop as a result. There's a reason why I think the game's biggest falling is that a lot of the new companions feel like extensions of the factions they represent rather than their own thing, and they felt very one-dimensional as a result. The fact that the actual companion quests were mostly stripped down didn't help either. Then there were the sidekicks - and it's kind of nuts that one of the prevailing opinions is that some of the sidekicks were far more interesting than the actual full companions, especially in the case of Ydwin and Rekke.
DOS2's companions were super one-dimensional too, but at least the writing and story was never the main selling point of that game. They were the main selling point of PoE2, and that makes the situation there even worse.
Oh yeah, PoE2's ship combat was shoehorned in by executives. That's another major misstep. Like the game had a lot of ideas but nothing that was really refined in the end. It's pretty telling that the expansions with a much tighter focus and not having to deal with external systems found in the rest of the game were received much better than the main game.
On the topic of Avowed, one of the main theories is that it's not a prequel at all. PoE2 has a couple hints that the next game in the setting was taking us to the Living Lands (including one quest which ends with the player character choosing one of two characters to exile specifically to the Living Lands for their crimes, which screams 'sequel outcome choice'). The footage in the trailer for Avowed looks like something that could resemble it, and honestly with how the region is described as a mysterious frontier island full of valleys with different biomes and unstable weather, a first person game would likely be more proper for the region than an isometric cRPG in terms of visuals. A proper PoE3 would likely take us in the direction of the other hinted region instead, Yezhua, which would need a more text-heavy setup to explore the implications of a region previously cut off from the rest of the world with people that had only worshipped one singular god instead of the pantheon.