City rankings can be motivational but unlikely to help city planners prioritise investment decisions. Bicycle Transport Analysis is a basket model for scoring cities for the suitability of cycling from the US. Canberra does very well in this ranking, but the first impression is deceptive as we are comparing ourselves with another LOW cycling country and not a good one like the Netherlands.
Would the 20-minute neighbourhoods work for the ACT? They could. We calculated with OpenRouteService for each town and group centre, the area no more than 20 minute distant for a normal cyclist. The green colour is 10 min and red shows the 20-minute distance. Most of the city is covered.
How easy it is to get around Canberra depends upon from where you start the trip. In some places the infrastructure is better than others. One way to study this is with isochrone plots.