Fully Vaccinated People Testing Positive for COVID - So How Does the "Benefit" of Experimental Vaccines "Outweigh the Risk"?

What are being called "breakthrough" cases of COVID-19 are popping up across the U.S. They're people who test positive 14 days or more after receiving their last dose of the vaccine. “It still is shocking that I’m positive. I have no symptoms," home health worker Hanna Rewerts said. The 27-year-old's vaccination card shows she received her second dose of the Pfizer vaccine on January 12. She said she found out she was positive on March 18 from one of the routine tests she takes weekly for work. Believing it might be a false positive, Rewerts said she took a rapid test, which also came back positive. She said her mother and two other family members – all fully vaccinated – also tested positive this week.

They are experiencing symptoms. “My biggest question right now is – is it still effective in my system?" Rewerts asked of the vaccine. Rewerts is currently isolating. She said she was told by the health department that she can resume normal activities on March 25, as long as she's not experiencing symptoms. “I think I’d just want people to continue to educate themselves about the vaccine and what’s best for them and their family. I still am happy that I got it, but I really would like there to be more research on the effectiveness," she said. In addition to media reports of breakthrough cases in Florida outside Tampa Bay, the Minnesota Health Department released an advisory earlier this month saying it was investigating instances in that state. It's asking health care providers to report breakthrough cases so that it can look into them further, along with the Centers for Disease Control and Prevention.

What exactly are the "benefits" that "outweigh the risk" of being permanently disabled or killed by one of these shots then?
Link: https://healthimpactnews.com/2021/fully-vaccinated-people-testing-positive-for-covid-so-how-does-the-benefit-of-experimental-vaccines-outweigh-the-risk/