I dunno man, agree to disagree on that one.
I'm all for preserving history and all that jazz, especially when it's as notable as Luna Park's, but appetites in the leisure industry have changed so significantly in the last five to ten years that it seems everywhere but Australia's amusement industry has risen to the challenge.
Places like Eat Street Markets in Brisbane are great example of the revolution there's been in F&B locally (and how premium, specialty foods print money and drive gate) and every research paper suggests the uptick in consumer drive for new leisure products is in the billions, not millions, year over year. Internationally, many equivalent businesses to Luna Park Sydney have invested in the last 3-odd years with major capex (Hydrus at Casino Pier or Iron Shark at Pleasure Pier come to mind), hell even the "OG" Luna Park built a roller-coaster, though admittedly not on the pier itself (and also, arguably not that great).
I think the point i'm driving home here is that against leisure trends and against global trends (COVID not withstanding) they're definitely, 100% dragging their feet on what could be an amazing opportunity to continue to innovate and add year over year. As you say, they've had major coasters previously, so I can only imagine the local market's appetite for the next "Big Dipper" to arrive, especially when there's zero competition in NSW. Furthermore, these kinds of capex projects always act as a halo for other products in a brand - their events business would thrive by having something well integrated, well executed and well marketed.
Could you imagine if there was a coaster flying around Luna Park with an epic light package like Hangtime at Knott's? At night, it would be iconic.