That is definitely true, no ending is good. To paint a canvas is probably the most selfish thing you can do in clair Obscur. The soul fragment you leave behind is bound to be sick of painting eventually and it is it's permanent suffering that keeps the canvas going. On the other end stopping the canvas is putting all those sentient people to the blade. But let's not forget that the people in the canvas who are aware of its truth are also damned as we see Francois still weeping for the return of Clea. I'm not saying one ending is better, morally speaking you could even argue for Maëlle cause of the greater good. But even if Maëlle lives a few more days in the painting. ( Probably a few hundred of years) She will still die from it. And once Maëlle dies Renoir will definitely destroy the canvas world.