That all depends on how you define "benefits". If you're talking strictly about the financial gains, then yeah...you'll never fully recoup the cost of hosting events like these.
But you'd also never have spent the money needed to build some pretty fantastic venues within the local community. Every time Vancouver has hosted some major international event, they built some pretty awesome attractions in the process. Some of those are still there decades later, and represent some pretty iconic additions to the local culture. If those events hadn't been hosted...those buildings never would have been built.
It's debatable whether it was "worth it" or not, in the dollars and cents sense. But everyone who lives there will tell you, having those venues in place now, is a part of what makes Vancouver special...so to them, it was definitely "worth it".