I see the only safe way to end all madness is all magic being removed forever.
The Fade is intrinsically tied to mortal beings. This is how Cole describes it as well as Spirits (if you help him become more like a spirit).
Spirit Cole:
"It is here (The Fade) but held, constrained by a construct, veiled. Feelings, memories, minds, mortality: All shape it, a glass to hold water, we (spirits) flow in the deep (Fade). Without you (Mortals), we (spirits) have nothing, not even us."
You can't get rid of it without destroying the world, as it is a product of life.
This could also be a reference to what is sustaining the veil rather than referencing The Fade itself.
The whole point in my opinion is literally the relationship between the "soul" and the body.
The Fade represents all that is spiritual and abstract i.e. feelings, memories, minds, imagination, will
While the "earth" represents all that is concrete. Sensations, touch, smell, sight, hearing, limitation, mortality, time. everything that holds our spirit and helps us express the spirit.
A delicate balance that is primordial and necessary, something that has been sundered by the veil.
That's why I believe Solas first saw us as less than people. unreal in his eyes as we were "incomplete", missing a fundamental part of ourselves, what he cherishes so, the spirit. We proved him this was not so yet his determination is unflinching.
It also explains his comment when he asks whether or not the mark has changed us fundamentally. Whether or not it changed who we were, our... spirit.
This comment is the precise moment that made him see us as people, because he needed to know whether our connection with The Fade due to the mark was the reason that led to him seeing us differently, as whole, as an example.
The fact is, our action,s who we are as a person is what defined the mark, not the other way around and Solas saw this.
People who lament it's loss and talk about us being a special snowflake because of it I think miss the mark (pun intended) completely. It also shows they don't understand Solas as a character and just how layered he is.
The mark was circumstance and opportunity.
Much like magic and technology. It is a tool.
How and why we use it defines us, not the other way around.
power is not inherently evil. Those concepts are developed by us, by our perceptions.
Here's a good example:
Ultimately, a demon is simply a spirit whose purpose has been perverted. Pulling a spirit unwillingly into the mortal world, particularly to achieve a goal out of keeping with its nature, will change a spirit into a demon (however, a spirit passing willingly through the Veil will not be changed[3]). Furthermore, an individual anticipating seeing a demon will do so, even if the entity is in fact a spirit.