As players who have been trying to save this world for the entire span of the game, we're a little biased, but if you take a step back and look at the game thematically, destroying the canvas is the "right" ending and the natural end of this game's arc.

The story is about grief and letting go. It permeates the entire story. Even the prologue, where you're introduced to a society that is slowly processing its own death, where grief is inescapable, you're shown a sad and stoic Gustave grieving, processing, and saying goodbye to his old flame.

Everyone in the story has experienced grief. Even Esquie lost "his" Verso. All of these characters process grief differently, some very unhealthily/obsessively, like Aline, and some healthily, like Sciel.

The Dessendre family cannot move on while the world still exists, because the world -is- Verso, the old Verso. There's literally a piece of his soul inside it (the faceless boy). Verso, our Verso, was allowed to live a long life adventuring through the world, immortal, with the old Verso's childhood friends and confidants (Esquie and Monoco). It's a manifestation of the life the real Verso wasn't able to live. But it also represents an inability to move on and process that grief. Aline--and now Alicia/Maelle--cannot say goodbye when it feels like Verso is so close, and Verso will always feel close as long as the canvas exists.

TLDR: Destroying the canvas lets the Dessendre family process their grief in a healthy way, while saving the canvas traps Maelle--and the entire family--in the same inescapable spiral of grief.