He doesn't suggest that the economy is a zero sum game, but that the distribution of that wealth matters and in our societies we're increasingly distributing wealth unevenly so that tiny minority of people increasingly control and own all the wealth, assets and means of production thus depriving other people of economic opportunities and crippling the economies.

In your example of building more, in order to a new building get erected someone owns the land, someone owns the materials, someone owns all the assets and the capital required to build. The people who invest to this will of course want to turn a profit on it.

"someone owns the land"

In England, only the King owns the land, and Parliament can deploy any resources in the UK it wishes by simple Act of Parliament.

The only other thing there is is human labour, and that can similarly be deployed if we choose to.

As we discover every time we go to war.

So no there is no cabal of hoarders preventing anything, and no shortage of stuff or money. All that is preventing regeneration is the political will to do so.

In reality Gary is a member of the Outer Party, and he wants to take money off the Inner Party and give it to his mates so they can all play at looking after the Proles while value signalling to one another.