I guess life would be largely the same except for the millions of dead people?
In general though, there has been a huge variety of policy responses across the globe and over time, so I'm not sure what you mean be 'we' 'shutting everything down'. My state came closest to shutting everything down for a month or so in the spring, but there has been a constant effort since then to adjust policy to balance health risks and economic/social pain. Italy had a super hard lockdown. South Dakota isn't even wearing masks.
It is also enlightening to consider the success of various strategies too. This will take years to piece together but one comparison from my corner of the globe is the contact tracing in New South Wales and Victoria. In NSW contact tracing successfully prevented a large second wave while in Victoria it did not, and they were forced into a strict lockdown which eventually worked. Remarkably, both states become free of COVID around the same time. There isn't much difference in socioeconomic status or population density between NSW and Victoria so the difference likely lies with the effectiveness of the contact tracing or just good/bad luck.
In general though, there has been a huge variety of policy responses across the globe and over time, so I'm not sure what you mean be 'we' 'shutting everything down'. My state came closest to shutting everything down for a month or so in the spring, but there has been a constant effort since then to adjust policy to balance health risks and economic/social pain. Italy had a super hard lockdown. South Dakota isn't even wearing masks.