I refer you to an excellent article in The Atlantic that explains the source of most current COVID-19 infections. Despite the commentary from misinformation campaigns, almost all infections are now caused by unvaccinated people. The Atlantic article presents data that explains infected, vaccinated individuals are much less likely to spread COVID-19.
This has significance for everyone, as exposure to infected individuals who have not been vaccinated is much more dangerous and more likely to require quarantine and testing. Also, this is essentially the only way vaccinated individuals get infected.
I hope the CDC director reads this given her agency’s poorly worded, confusing comments on this topic!