Necessary, because if it were not true — if large-scale government projects NEVER enhance the welfare of society — then we have no reason to think that the lower chance of funding for large-scale goverment projects under government by referendum is something that hurts society. If the projects don’t help in the first place, what’s the harm in not having those projects funded?

Not necessary, because the author never compares government-executed projects to projects executed by other things besides government.

Not necessary, because the author’s theory for how government by referendum harms society relies on the decreased chance of funding for large-scale projects. The reasoning isn’t based on anything related to harm to the democratic process.

Not necessary, because the author’s reasoning isn’t based on the purpose of how political power is distributed. The author argues that a certain kind of government will have a certain harmful effect; that doesn’t require an opinion about purpose. Even if enhancing welfare was only the second or third main purpose of equally distributing power, that doesn’t undermine the author’s reasoning.

Not necessary, because even if there were other ways to distribute power equally and widely, the author can still argue that government by referendum tends to have a certain effect. Other government methods may have worse or better effects; that doesn’t change anything about whether government by referendum can hurt society.