Max the Axe is always right.
Flow rates are artificially manipulated by LTOP (noise sharing) modes and movement caps.
However, Max is surely not suggesting that the 39% is in the peak period, even though it's implied for the weak of mind.
If he is suggesting that, it would make SY more 'efficient' than LHR, which it could never be with the current ground infrastructure and design (layout) issues including the shorter runway.
The reality of politics from both sides is a decision to allow KSA to be utilised correctly will cost lots of votes, long term votes. I don't see either side doing anything to make KSA be used as it could be. And most know that.
Even the airlines are starting to get behind a new bit of tar. It will cost short term votes elsewhere because it will in itself generate jobs, votes and lots of construction/development. The long term loser will be SACL and Max knows that! I'm sure he is posturing to ensure they get the rights to own the new development, and if they do then I suspect the new project will never be what it could be.
A corporate CBA would never stack up as it's not replacing the existing infrastructure e.g. Berlin/Bangkok etc; not to mention the costs airlines would need to invest on their individual spends. So it has significant public money, and where does that come from? Bring on 2025 before a real decision is made.
Of course if the movement rates were reduced even more, the CBAs would start to stack up...