I am a bit split. If I’m reading it correctly, Wiki’s source is a journal’s comparing their simulation of what Sydney’s economy would have been without the Olympics, and the numbers published officially, with a twist on additional costs they think should be added to the official estimates.

> We simulated the behaviour of industries, households and government resulting from hosting the Games for each of eight Australian regions over the years from 1997 to 2005. Our results revealed that rather than producing an economic benefit the Sydney Games actually reduced Australian household consumption by $2.1 billion.

For comparison there are later reviews of the economics of the town with the 6 years after Olympics, with less simulation apparently, which come to a different conclusion https://repository.tcu.edu/handle/116099117/10360

I honestly don’t know which one is more trustworthy