People are regularly exposed, every season we have X million exposed, and 5% or whatever are severe. Due to the pandemic we basically skipped 2X exposures that would have happened, so now we are having 2-3x all at once. Even if the same 5% were severe, it would be bad. That also ignores two other factors, viruses spread better in populations with fewer immune individuals to act like fire breaks, and we also probably put selection pressure on flu and rsv to be more contagious (to allow survival during covid measures). All of that together is probably a perfect storm of infection. We are probably infecting a lot more people per day than a normal year due to all these factors.