The floating runways are a none starter IMO, and expanding any airport has it's own problems..So it may as well be Heathrow.
Sorry, your conclusion doesn't logically follow from your premises.
You could equally well have written:
"The floating runways are a none starter IMO [agreed]
and expanding any airport has it's own problems.. [agreed]
So it may as well be a new (non-floating) airport in the Thames Estuary".