What other sport has nine teams with the same home ground?!
Your question sums up the insanity of having nine professional rugby league clubs from the same metropolis playing in a closed model national competition. The fact no other closed model national sporting competition does this, with the exception of AwFuL, explains why we need to stop propping up nine small Sydney clubs when we have other important markets without a team.
The NRL artificially props up all nine Sydney clubs.
Let's get rid of the salary cap for ten years and introduce promotion and relegation, with no annual grant from the ARLC, to see if Sydney can support nine teams, yeah?
How many Sydney clubs will still be in the top flight by the tenth season?
If a national promotion and relegation competition has nine clubs from the same metropolis in it then they've proven themselves to be strong enough to compete with clubs from other areas.