You are right I have not read all the Davies report, perhaps I should. However having been in the aviation community for 34yrs, started flying ex LHR in 1969, when it then had 3 R/Ws I have observed that environmental interests always prevail. Take the building of Munich, Oslo, CDG, HKG, a/p's etc, plus numerous battles for extra R/W's at FRA NRT MAN.
So the normal progression is extra terminals, ie the original T2 extention plus T4 at Lhr leading to the closure of R/W 23, then T5, and so surprise surprise an airport becomes capacity constrained
The UK was urged in Dec 2002 by IATA to expand Lhr capacity, 13yrs later zilch
No politician is going to have the bottle to bulldoze circa 1000 homes and subject 8 million Londoners to twin parallel approach noise paths throughout the day.
Most major airports have night curfews, and one thing Davies did say was "no movements before 6am" Current Lhr will not be able to comply with this.
Having been in the business and seen worldwide the effects our operations conflict with those below, I am convinced the tiny % of business travellers viz the rest will not win this arguement