That's what you're implying and looking through your posts, it seems that you're using constant circular and misdirecting arguments to avoid talking about the inherent fundamental problems within DA:I.
Let's forget about the story and go to gameplay then, which one of these is objectively better? It can be subjective, but I'm asking in terms of mechanics within an RPG.
"Combat in Original Sin is turn-based and tactical, and positioning and environmental factors play a huge part in determining the victor. All of the elements—fire, water, electricity, poison, etc.—interact with one another, as well as with characters. That means that you can break a water barrel to make a huge puddle, then electrocute anyone standing in it for extra damage. Or, an explosive arrow can set off a chain reaction, igniting a cloud in the air and laying waste to a poorly-placed enemy platoon. Characters can be wet if it's raining, dry if it's sunny, warmed by a fire, burning, and plenty of other statuses, and each one affects how they fight, how much damage they're taking, and so on."
Or, picking the specialization of say, Reaver, and spamming Dragon Rage with the occasional swing of the weapon with Devour for minutes on end? I say that because that's what combat as a Reaver boiled down to vs. Not that in DA:O.
There is no argument that in terms of combat - or at least let's say isometric RPG combat similar to IWD or ToEE - there is no competition with Divinity, and Divinity included a lot of features really designed to make that work. If isometric combat alone did it for me, I'd still be playing Divinity. But it doesn't. Just like IWD didn't. I don't like games like that beyond the time I spent breaking their combat with a powergame build.
There's a separate question as to whether or not DAI and DAO succeed with their own combat, whether the mechanics are better than DAO, and whether the UI is better in DAO. I need to add the caveat that I've only played DAO on nightmare (aside from my first PT ages ago) and I'm not yet done my first DAI play through, and haven't played it on nightmare yet. Also, I power-game, so that strongly colours my feelings about what RPG combat ought to be like.
I haven't played reaver in DAO and now never will so I can't comment. I play mages. And I found mages in DA2 and DAI far superior, with my favourite mage gameplay coming in DAI.
In DAO, mages were broken in two ways. Some abilities were so OP (like Mana Clash) that they made the game pointless. And others were so **** that they only existed to eat up ability points to get to the good stuff. There was only one stat that mattered in DAO for mages: magic. Even as a BM, constitution really only mattered as buffed by items. Each level up was just dump 3 points in MAG or built suboptimally.
In terms of abilities, like I said, there were two choices: trash or OP. Some abilities had good synergy with some builds - Spell Might and Wisp come to mind, the former because it drained mana even if you used BM so it was just a free spellpower boost and spell wisp because it added. I easily had 150 spellpower by level 20. But otherwise there was no variability.
As for tactics, every mob died the same way: fireball (which knocked them down), cone of cold when they ran for me, and then basic damage abilities like winter's grasp and arcane bolt to finish. If I used two mages or the BM/SM they wouldn't even get that far. I tried to gimp myself - not use paralyse or glypth or paralysis to hold them in place - but not even that made it challenging.
For my play style, the tactical camera and action mode work well because I prefer a mix of WASD and click to move depending on the circumstances. I hate aspects of the tac UI with a passion, especially that I can't multi-select and that I can't rote or zoom out the camera properly, but overall it works for me. I don't mind moving the camera with WASD because that's how I moved my characters.
DAO and DAI control very similarly for me. WASD to move, low angle zoom on the camera because I don't care for top down, I need field of view in the distance. So I would always be one scroll flip below pure isometric and angle the camera into the distance.