But also 15-18 is a crap crowd. At least relative to the strongest sports code in the country and just about every other pro football code in the developed world.
Don’t compare to AFL. It is worldwide freak for crowds. Relative to population, it has the highest crowds in the world. MCG is almost the highest attended stadium in the world. Their model is based upon huge CBD stadiums which is not what the clubs nor the fans want for RL in Sydney. If you want to be like AFL you just close all stadiums besides ANZ, SFS and Parra. RL in Sydney has something that every other code has lost - suburban teams playing in their suburb. This must not be lost.
Take the AFL out of the comparison and 15k - 18k in a packed local stadium in the suburbs is brilliant. If you add in a handful of blockbuster games at BankWest/SFS/ANZ and factor in the overall NRL average would push 20k if every Sydney club was filling their local stadium each game. That would put the NRL around 20th best of any league in the world - and every league above them is in a country with more than double the population of Australia. For a sport that only half the country follows, an NRL average of 18k - 20k would be excellent by world standards.
If you don’t bring local grounds up to 2020 standard, crowds will continue to decline. The average at local Sydney stadiums in recent years has been around 13k, so 15k - 18k would represent a 25% increase and would be terrific.