Warnervale has rapidly encroaching development and very strong commercial pressure to sell land for industrial use. I've flown over Schofields a few times. Funny to still see the remnants of runway and aerodrome surrounded by housing developments. Richmond has a number of serious limitations.
The pollies, bless their souls, need to friggin' make a decision, stick to it, and not succumb to the greedy lure of housing/industrial development dollars. And what are the chances of that happening? Unfortunately when it comes to a 2nd airport for Sydney, it is bipartisan greed and incompetence as far as the eye can see.....