> There's something fundamentally wrong with the idea of deciding for people what might improve their lives and what isn't allowed to try

I disagree, I don't think this at all an a priori wrong. It's helpful to consider the limit case.

If we lived in a world, for instance, where one person owned all of the food in the world and didn't want anyone else to eat it, it would be permissible for the other 7 billion people in the world to "decide for" that one that their food will be redistributed.