If I break both of your legs, that's serious. You're not dead.
If you catch AIDS, that's pretty serious. You're also not dead for a pretty long time.
If I poke your eyes out, that's serious. You're also not dead.
You've redefined a serious medical problem at one which kills you. COVID19 disables far more people than it kills. We don't know how many more, and we won't know for quite a while. With lung damage, most doctors believe the damage is permanent, but some believe people will recover in a decade or two. With other organ damage, we're just speculating.
If I break both of your legs, that's serious. You're not dead.
If you catch AIDS, that's pretty serious. You're also not dead for a pretty long time.
If I poke your eyes out, that's serious. You're also not dead.
You've redefined a serious medical problem at one which kills you. COVID19 disables far more people than it kills. We don't know how many more, and we won't know for quite a while. With lung damage, most doctors believe the damage is permanent, but some believe people will recover in a decade or two. With other organ damage, we're just speculating.