Those pie charts are not the full story though. If people were evenly vaccinated across the population they would be, but as it stands the "Fully vaccinated" population are the oldest and most vulnerable section of the population, the "partially vaccinated" are 30-50 year olds (mostly), and the "unvaccinated" are mostly children or under-25.
Therefore it should be unsurprising that lots of younger people and school students (who are the only group able to freely mix in large numbers indoors with minimal distancing) make up most of the cases, especially as they are tested regularly even when asymptomatic.
Older and more vulnerable people, all things being equal, should make up over 90% of the hospitalisations and 99% of the deaths, that they are not is the result of vaccination.
Also, there is not yet full data separating those in hospital because of Covid from those testing positive while in for something else. Older, more vulnerable people (ie the fully vaccinated) are far more likely to be in hospital for something, so their asymptomatic or mild cases are more likely to be recorded as Covid hospitalisation than the general populace.