Part of the problem there is that DA2 is all set up with very little pay off. I wouldn't go as far to say it has no pay off, your companions at least get resolution in each of their own personal quests, but as for the grand plot of the series? I think Merrill's personal quest is the best example of this.
Throughout the entire game we are told about how important Merrill's mirror is, how it is something that can change the fate of the evils, if not all of Thedas and implying that it will mark a important point in this worlds history that you will bare witness to. Only for it to not matter as Merrill never finishes her Eluvian so it just ends up sitting there for the rest of the game. Same thing with the Red Lyrium, the whole game keeps asking what is up with this lyrium and Varric even gets a piece of it only for it to not going anywhere.
The Amazing Spider-Man film series had the same issue, set up with no real pay off makes every chapter buildup to a later chapter making the events of the chapter you're currently witnessing pointless. DAI handles this a lot better IMO as there is set up for future games and teases but you only noticed that in future playthroughs and DLC's like The Decent and Trespasser. DAI answers what Eluvians are and what they can do, and we learn a bit more about Red Lyrium and what's the deal with it.
Other then that, not counting side quests that are intentionally setting up future games, every major goal the characters and the player set for themselves is pretty much fully resolved at the end of the main game. The only exception is Solas who's goal is never achieved and meant to set up future games but other then that, all your companions find what they were looking for and you solve the main story and complete every task given to you at the start of the game.
Again, DAI is where I really started with the series and I had no real problem following the plot or figuring out who anyone was. Varric, Cole, Cullen, Casandra and Leliana were characters from other points in the series but they gave me their basic backstory so I didn't feel like I needed to go and read/play the previous entries in the series to know who they are, I just had to ask them.
Going back and playing/reading was something I've really only recently done and that has only added to the experience because the stories that buildup to DAI were enjoyable in their own right. DA2 is, IMO, the weakest of the lot but I still enjoyed it despite its flaws much in the same why I enjoy the Star Wars Prequels, (though I think the Prequels are better then DA2). But Asunder was well written with a generally likeable cast and a strong, if bitter sweet, ending and I would recommend it to anyone who is a fan of the series.
