First, this is a study of those who got myopericarditis after vaccination, it doesn't mean 90% of people got myopericarditis . Of the 100% that got myopericarditis, 90% needed 'hospitlization'.
But you ignored rest of it as usual to suit your preconceived conspiracy theory.
Although 92.6% (95% CI, 87.8%-97.3%) of patients were hospitalized and 23.2% (95% CI, 11.7%-34.7%) of patients required ICU admission, inotropes were used in only 1.3% (95% CI, 0%-2.7%) of patients, no patients died or required mechanical support, and the hospital length of stay was 2.8 (95% CI, 2.1-3.5) days.
Take another L, your bad week continues.