Sure, but you can do this while still allowing a partial reopening. No mass gatherings, reduced capacity in restaurants, etc.
Hell, the virus spread rapidly throughout NYC for weeks completely unabated with no restrictions whatsoever and the healthcare system in the city was still able to hold up (albeit under very strained conditions).
A full lockdown is unsustainable for an extended period of time.
You cannot, a partial lifting of restriction will increase infections, and we still don't know you cannot be reinfected, or that the virus cannot mutate into a second wave.