I promise this thought is Dragon Age related just bear with me for a moment.
I used to work in trails and environmental restoration. So we would deal a lot with invasive species. One important concept in ecology is naturalization, where you have an invasive species that’s been around long enough that other species evolve to deal with it and live with it. It’s a major mechanic of evolution and happens even when humans aren’t causing it.
When I think of the Veil, that’s how I see it. Tearing it down would restore an ecosystem that no longer exists in its original form. There’s no telling what the effects would actually be with magic tearing into mortals like that. We also know that Solas’ original ritual went wrong and there’s no guarantee tearing it down wouldn’t cause new, even worse problems. Or create something worse than the Blight.
It’s not like dam removal, where a lot of animals die in the initial destruction but the population bounce back is incredible, because those fish species are supposed to be there. We need them back in the ecosystem because hundreds of years haven’t passed, there hasn’t been time for the system to figure it out without them. Not to mention we’re talking sentient beings who did nothing wrong who would die in the process of tearing itdown and not fish but you get the gist.
I stand by the Veil remaining intact and Solas being its guardian, because he broke the world multiple times trying to save it and frankly, it’s someone else’s turn. The mortals of Thedas deserve the chance to steward their world, especially that they’re finally free from the meddling of the Evanuris.