The vaccines are doing their job quite well. Preventing major illness and death. Breakthrough cases happen, but are nowhere near the problem unvaccinated people are. I don't think the problem is normal healthy adults needing a 3rd vaccine. That isn't the reason hospitals are clogged. The issue is getting unvaccinated people vaccinated. I can't fathom why health care workers aren't mandated to get vaccinated or why they wouldn't want to be.
3rd vaccines should be available now for old people and immunocompromised people.
It's not the reason hospitals are clogged but it's contributing
My sample sizes aren't statistically relevant, but I've seen the average age of covid patients get way way younger.
And let's be honest, less than half of adults are normal healthy adults