It'd be nice if Bioware could actually make an engaging boss fight to demonstrate the high stakes of it all
but they won't, because they don't know what to do really. If Solas is an endgame boss he'll probably be given generic and basic attacks that look dull and ordinary and don't do much damage.
I don't think they are incapable of it. BUT, there is something to be said for the difficulty levels and designing encounters based around that.
The difficulty setting can go one of two ways. The first is that they can make a complex fight, as Corypheus in the Legacy DLC, and simply have all abilities deal less damage the easier the difficulty -- this is my preference. The second is that they can make a fight whose mechanics change, and become more complex, as the difficulty increases (I don't know the game dev logistics of executing this method) -- I wouldn't want this, as I would prefer to see the fight as it was intended; the baddie shouldn't forget how to do something simply because I lowered the difficulty setting.
Unfortunately, I was unable to finish the final fight in Neverwinter Nights 2 on the easiest difficulty, after many attempts, looking up strategies online, and so forth. Maybe it's because I didn't build out my party correctly, or simply because I suck. I'm OK with being bad, and maybe I didn't deserve to win the game (I know there are some players who would think this), but it was extremely demoralizing to continually fail over and over and not be able to do anything about it. I eventually just gave up and never picked the game up again. This is the only game this has ever happened to me.
I am not averse to combat in games; I raided for many years in World of Warcraft. My argument for a combat-less finale is not because I dislike combat, it is because I want something different. Also, with the way they're setting up Solas, I think that is deserving of something different. I think it would be lame if he were given basic attacks and the player slowly whittled down his health and then won, or if there were some sort of deus ex machina that was used to defeat him. That would be a terrible way to end things.