We are trying to buy time. You're right; the second wave is likely to occur in the fall, when kids go back to school and normal activities will have resumed. Until then, reducing close contact with people is a must.
We've learned that the virus spreads when people are in relatively close contact for a relatively prolonged period, so it spreads much more effectively indoors than outdoors. It's probably relatively safe to let people go outside, but they need to stay two metres apart, as much as possible. Even when people are a metre or a metre and a half apart, with dilution, warmer weather and humidity, the virus is a bit less resistant, so it shouldn't be transmitted as easily.
I think people need to get used to wearing a mask in public, but not necessarily outdoors. Wearing one in confined spaces where people can't stay two metres apart the entire time is definitely necessary.
As you said earlier, we have to learn to live with the virus, because it's here to stay in the short term. We have to wait until a drug or vaccine is available in order to protect the entire population.
We know transmission is going to occur, but we have to find ways of reducing it as much as possible. We don't want to have to force people into lockdown all over again because transmission has picked up too much.