Looking at departures from Heathrow today show something like 2,700 seats going to Amsterdam on 20 flights. using 5 or 6 A380 on this route would please the environmental lobby no end.
This may come as shock, but "the environmental lobby" has no influence on airplane sales. zero, nada, bupkis. And operating a huge airplane like the A380 on such a short range city pair as London-Amsterdam would be highly inefficient and a quick way to lose lots and lots of money.
Departures to Frankfurt show similar numbers so using A380s on both these routes would mean something like 10 movements per day between them, compared to the current 36.
Flights to New York by BA alone today will have something like 2900 seats on 11 flights. That could be reduced to 7 A380 flights.
And so it goes on.
Do you see what you did here? You looked at just a small handful of city pairs. Yes, the A380 is wonderful for a few handfuls of city pairs, but for the great majority of city pairs, its simply too much airplane. Too much as in it can't operate from the vast majority of airports and too much as in there aren't enough passengers to fill such a large plane even assuming it could land there.
Second, you fail to recognize that there are multiple airlines serving the vast majority of city pairs. One simply cannot assume, as you did, that one airline will get a monopoly on certain city pairs and be able to reduce the number of flights. There is competition for almost every city pair and airlines have great difficulty filling an airplane the size of the A380.
As for governments "limiting movement numbers" that seems highly doubtful. Further, governments "pushing airlines into operating fewer services carrying the same number of passengers" is also highly doubtful considering that most airlines operating into and out of any given nation are foreign owned and controlled. And even if the governments magically made this happen it would happen for only a small handful of airports.