The NBN isn't great, but lies about performance aren't the problem.
We do have independent testing by end-user devices though (SamKnows whiteboxes), similar to those used in the reported US study. We have also sold-off one government owned monopoly wholesale provider with crummy infrastructure that treats its retail customers like sh!t for $60 billon(ish), and replaced it with a new one, but at a cost of $50 billon (2019 estimate).
Not sure about the "most technologically advanced nation in the world" claim. Isn't that Estonia?