In part because LA was the only city to bid on the 1984 Games and so could negotiate better terms, and in part because it got an especially lucrative TV contract, worth more than the declared profit. And in part because all sorts of externalities from environmental costs to traffic to and more aren’t calculated in.
You mean by 2028…or ever? 
Los Angeles will never opt out of the Games. They’ve wanted them desperately for decades. For heaven’s sake they FINALLY built a rail transit line to the airport because of it!
If the Supreme Court enforced the constitution as written, Trump would have no power over tariff rates, and then I would agree with you.
But the way it is now, few national leaders dare to seriously cross Trump for fear of him raising their tariffs.
There is some line past which you would be correct. If there was a major war going on between the U.S. and Canada, I suppose that would cause dozens of Olympics withdrawals. But I doubt Trump will go that far.
Two things I can guarantee:
- Trump will almost always “go that far”, and
- Almost nobody will come back and publicly apologize for saying he couldn’t possibly do so.