you can see here plenty of articles citing profits for ~50% of olympics: https://en.wikipedia.org/wiki/Cost_of_the_Olympic_Games (estimates obviously don't include a bunch of intangible costs/profits).

I'm sure you could construct a list that shows no profits ever, and a list that shows massive profits every time (using the same level of evidence for both sides).

the primary issue is that it's extremely difficult to measure costs/profits for something as massive as an olympics. the secondary issue is that people tend to support their 'sides' narrative (keynesian or otherwise).