I think this is a really cynical viewpoint. I understand why people have it, but it’s a stance completely absent the character’s emotional state and growth.
From Wanda’s perspective, it didn’t matter that the life was an illusion/delusion. It was, for the first time since her parents were killed, happiness. It was peaceful. And I think wanting to obtain and keep that feeling after a lifetime of trauma is completely relatable. Facing and accepting grief and loss is a terrifying prospect that people don’t willingly accept. Most people, if they had the ability, would absolutely bring back from the dead people they love and create a perfect, safe world where they can live. A lot of people if given the choice of making other people uncomfortable for the sake of their own happiness, would selfishly choose happiness. Monica says as much. What Wanda chooses, in the end, is personal grief, loss, and trauma for the greater good over her selfish happiness. It’s arguably the most “heroic” act she’s ever made. Yeah, she tortured a town. She also chose to release them once she saw what it was costing them. Because it wasn’t until the final couple of episodes she was fully cognizant of what she had done. Her happiness made her oblivious. That’s actually fairly accurate to addiction, trauma, and grief.
Super hero stories are littered with this exact character conflict. The central character conflict in Raimi’s Spider-Man 1&2, and Iron Man 3, especially, focus on heroes struggling on if they should let the nameless masses suffer so they can find personal peace and happiness. Those films, however, never focus on what that means for the masses. Wanda addresses it directly because Wanda’s powers drastically increase the scale of that conflict. Wanda can bend reality. But emotionally it’s the same story.