What line of thinking do you subscribe to then? There is no scenario in which no one dies from this disease. Therefore, in every scenario there are going to be some number of people that die. Even in New Zealand, where they immediately closed all borders and implemented strong social distancing after learning of the virus, some people have still died from it. Much less than other countries, but some deaths.
We have to live in reality. While there are some developmental treatments and vaccine candidates which are showing promise, those are not guaranteed to work and there is no firm timeline for when they might be available. Absolute best case scenario for a vaccine is this fall/winter, per medical experts but that is like the one in a million absolute best case. Therapeutic treatments could possibly be ready sooner, but those treatments don't guarantee recovery.
The U.S. and World economies can't withstand several months of complete shutdown. Even if we could leave the economy "off" until a vaccine and magically flip the switch back on after the shutdown and put everything immediately back to normal (we can't) after the entire world was vaccinated, then we would start running out of essential supplies before the fall. We're already running low on chemical reagents needed to perform coronavirus tests, along with many other medicines due to supply chain issues.
This virus is out now. There was a chance it could have been contained had we taken stronger measures at the federal level back in January, but we didn't. It's in so many places we don't even know where it is. Our best strategy is to keep it at a slow burn. Develop and strictly enforce new workplace rules designed to keep infection rates low. Slowly release restrictions. Keep the economy running at least at a trickle for the next year or two until we have better treatment options.
As much as it may seem distasteful or disagree with your own personal morality, these are the decisions leaders have to make. All choices will cause deaths and loss of livelihood for Americans. As a leader, you have to decide which one causes the least hardship. I'm not saying this to try to make past decisions by Trump or Reynolds look better. I'm saying it because going forward even the best leaders in the world are going to be re-opening their countries prior to the development of a vaccine. Look at Germany, South Korea, Taiwan, and other European countries - they will soon (or have already) re-opened to some degree.