Governments know that it is not only inevitable that a large part of their populations will be infected with and suffer illness from COVID-19 - they actually need this to happen, because (in the absence of any vaccine), it is the only way to eliminate the virus from their population.
It works like this. Viruses can only live, multiply, and pass through the population if they find suitable human bodies to inhabit for a while (outside human bodies, they die quite quickly). Now, on the whole, a human body that has suffered an infection and recovered from it will have done so by creating antibodies specific to the virus, which will make that body highly inhospitable to future virus visitors of that type. That body then 'has immunity' to the virus in question.
But that's OK, so long as the virus can jump to another previously uninfected (and hence vulnerable by its lack of antibodies) human body, and live and multiply there for a while before infecting another previously uninfected body when the last one has itself developed antibodies and become inhospitable, i.e. immune.
When a virus is new to a population, life is easy. it can find lots of fresh bodies to jump into. But when a substantial proportion of the population have contracted the virus, become ill, then recovered, hence possessing immunity, then when the poor little virus is kicked out of one body it can find nowhere else to go ... and it dies.
Poor little virus!So, when a large proportion of the population (it does not have to be 100%) has contracted the virus, become ill, recovered, and hence become immune ... the virus actually dies out through lack of suitable hosts. That's called 'herd immunity'. That's what the US population, and every other population, needs to do. It's the only way to make the virus go away.
The trick, however, is to slow down the rate at which the population is infected to the point where the number of sick people needing intensive care is always within the capacity of the available hospital beds. That's hard to do ...
Of course, the US government, or any other government, can't tell people 'Hey! In order to beat this virus we need a lot of you to get sick! Do your duty as good citizens'. True as it is, people don't want to hear that, even if it would be the honest thing to say. And of course the fact that it is the honest thing to say makes it extremely unlikely that Trump will ever say it.
FOOTNOTES:
What about vaccines?
Vaccines are a clever immunological trick to make your body produce antibodies without you having to catch the virus and get sick. But they are irrelevant to COVID-19, since it is highly unlikely that a vaccine for that virus can be developed in less than a year from now.
What about locking down cities, and stuff?
That's basically a tactic, first tried in China, to make the mass infection - herd immunity - virus die-out cycle happen in one limited population segment, so it does not have to happen elsewhere. It's not very likely to work in the US by the look of things.
So (hopefully slow) mass infection is the only way through this. But that is not a nice thing to have to tell people, is it?