I remember when we use to get big acts but they seem few and far between lately. This year would of been a great opportunity to get a big act for such a crappy year. So who do we get? Amy Shark? She has 1 charted album and 2 singles in the Oz top 10. What is she going to do after those 2 songs. If your not going to get a big International act then atleast get an Aussie band/performer that has a big catalog of catchy tunes. Someone like Chisel, Powderfinger, Silverchair, Midnight oil, Ac Dc etc etc. I know half those bands are broken up but getting them back for the day. Would make it an even better event.
She is probably much cheaper than any of the acts you mentioned, and when you consider that the NRL have had a significant revenue cut for this season, and can only sell 50% of the number of tickets to the GF, if you then expected a major big name band then you were being extremely un-realistic.
Even the AFL have gone low budget in terms of the bands they have for their GF this year.
People in past years question why the NRL don't get acts of the level that they do for the NFL Superbowl in the USA. Well the major difference is that ticket prices for the Superbowl factor that in with many tickets being north of US$3,000. So if you want big name bands, then expect the NRL to jack up ticket prices to pay for it.
If you don't like Amy Shark, that's cool. Personally I've never heard of her. Its just I'm tired of people not realising, year after year, that if they want a big, well known act to perform, then they will expect to be paid, and that will cause an increase in GF ticket prices as a consequence.