Maelle never asks for Renoir to spare the painted people's lives on behalf of themselves. She doesn't make the plea that they're living people who deserve life and that him killing them all is wrong. She only ever asks for the canvas to stay because she finds it fun.
Maelle doesn't see the people in the canvas as real people. They're essentially video game NPCs from her point of view. They have no real emotions or free will.
This means that the Verso ending is objectively the correct ending, as the Maelle ending is just Alicia becoming a NEET and locking herself in her room to play The Sims until she dies.