Not just that though, I already tried to address this issue earlier in this thread, but that was more an exercise in math than anything else. You can reduce complexity while still adding depth to the gameplay. I don't know for sure if DAI will be like this, or if it will be due to or excuse the 8 ability limit, but there are some hints and indications from what we've seen that it's probably going in this direction of adding depth to the abilities there are, instead of relying on a breadth of abilities to create choices and strategies in combat. How far they're going with this is what really remains uncertain.
A cone of cold against a cold immune/resistant mob, no matter how modded, will be a wasted spellslot. Shield Bash, against an immune/highly resistant mob will be a wasted skill slot. Depth of skill won't change anything if it's effects are minimalized or neutralized by the target. Meaning that, regardless of how deep these skills are, there may well be circumstances where they're useless. This means that, in order to prevent yourself from being locked out of stuff that may be useful when other stuff isn't, you're not going very deep into any skill, because the points are, presumably, limited by your character levels. You may be able to get away with these investments with some of your companions, depending on how their skills/specs are set up, but really, if you really like Viv, are you going to be willing to leave her in camp for an entire map because her spec's direction makes her completely useless in a specific area? Isn't this "depth" taking away from RP opportunity then, thus making it more shallow instead?
So far the number of active skills is roughly the same as DA2, but we now have far more passive abilities along with the 8 ability limit. If that's all they've done with combat then yeah it's probably going to be kind of a big let down. But if they also are adding more depth to the abilities, then the 8 we do have could end up being much more versatile and useful in combat than the 15-20 we may have had before.
If they take the CCC system from DA2, which we know is returning for sure, and build on top of the Brittle, Stagger and Disorient status effects by adding more abilities that create these states and can exploit them, as well as adding other states that can be exploited then we will have a combat system that on the face of it doesn't have a lot of options, but underneath actually provides a great deal of diversity and opportunity in combat by combining these various abilities to inflict useful statuses and massive damage.
If this is what they do, which I really hope they do, you won't simply be attacking an enemy with a fire spell cause it's strong and they're weak to it, but you'll also be attempting to give them the status effect of Burning or Fear or whatever which another companion can then exploit with one of their abilities for far greater damage and effect. If crafting feeds into this and creating weapons and armors that help boost your chances of inflicting these status effects, or prolonging them, is in place that will add another layer to combat and the strategies you employ by giving you greater reason to prepare and plan ahead and create your own equipment.
You will be planning ahead different strategies that your party can preform to devastate and make quick work of enemies. Some spells or abilities could weaken an enemy allowing another ability to inflict a status effect more easily which then allows for a third ability to exploit that status for serious damage. You won't just be spamming the same 8 abilities because they do the most damage, instead you'll have strategies in place based around how they effect the enemy and overall battlefield, using them in a more deliberate and calculated fashion.
So the game won't simply be about exploiting inherent weaknesses in enemies but also creating your own and capitalizing on both. Say an enemy has a weakness to fire so you have your Rogue hit them with an attack that inflicts Disorient and then have your Mage strike them with a Fireball which they're already naturally weak too, but on top of that it can inflict even more damage while they're Disoriented. That built in layering effect adds to the game in ways that a multitude of mostly static abilities may not be able to.
Actually, using what you've laid out here, if I'm using a fire spell against a mob that's vulnerable to it in order to create ccc's, that's exactly what I'm doing, exploiting their weaknesses. The way I'm going to do that? I'm going to look at the ingame Prima guide provided with the tactical camera: I'm going to sneak a peek at what I need, and rebuild my party accordingly. Wasn't it you that said that that's cheating? I mean, what's the difference between having the strategy guide on the desk, or using the ingame provided version? Because it's in game it's not cheating, or more accurately here, metagaming? To my mind, metagaming what I need for an encounter is metagaming what I need for an encounter, whether it's using in game tools, save scumming, or the Prima Strategy Guide, all provide the same results; advance player knowledge of how to prevent myself from failing/making the combat easier.