This isn't necessarily true. It seems to be a localized issue.
For example...
Researchers studied COVID cases at the Houston Methodist healthcare system and identified 862 people with symptomatic omicron infections from late Nov. to Dec. 18, 2021. The study, published Sunday, reported that early signs show more people are getting infected with omicron despite being vaccinated. Patients with the new variant are "significantly less likely to be hospitalized," and the disease is less severe overall.
Of the patients with omicron, 430 of them had been vaccinated, and researchers state that compared to patients with other variants, omicron caused "a significantly greater percentage" of breakthrough cases.
Additionally, according to the study, nearly 9.9% of omicron patients had received a COVID booster.
Omicron caused more breakthrough cases than Alpha or Delta in the study.
justthenews.com