This is true but slightly misleading : if 100% of the population was vaccinated, 100% of hospitalizations would be amongst vaccinated people.

They would be a much smaller and manageable number, and on average much older/vulnerable than they are now (vaccination basically lowers your risk to that of someone 20-30 years younger)

More figures from France : the unvaccinated 8% account for 39% of hospitalizations, 54% of intensive care admissions, 46% of Covid deaths.

This is a hugely outsized effect, so there's still enormous potential for drastically improving the situation in hospitals with just a few more percentage points of vaccinated people.