Comparing a countries overall population density is a rather crude and meaningless metric.
Friends I have from New Zealand have balked at the stereotype. As though they're all living remotely and tending to their sheep. In reality countries like Iceland, Australia, NZ, etc have the vast majority of their populations living in urban areas.
83.4% in the UK
86.5% in the New Zealand
https://en.wikipedia.org/wiki/Urbanization_by_country