Surely you can argue about library upgrades on a philosophical basis though? Maggie Thatcher didn't like the concept of "free" libraries. Libraries began as private/subscription services.

Gattung is both entirely wrong and entirely right.
The Mayor doesn't have a lot of power, and neither does Council. But they could. The politicians do not set the right goals nor do they take a sufficiently active role in guiding the actions of the bureaucracy. There is more concern about the colour of a library's paint job, or the technical details of a bike lane, than there is about the effect of those decisions in terms of social, economic, or cultural outcomes.
My hope is that if Goff wins, instead of worrying about specific projects, he will change the debate to the kind of outcomes we want - faster or more accurate building consents? Fewer beach safety warnings? Shorter commutes? Rather than focusing on specific projects. As a former Minister he may have the experience of managing for outcomes and purchasing outputs that current Councillors lack.