Some of the UK/US response was supposedly based on this study [0], which predicted maybe 250,000 deaths if there was no lockdown. That's something like 140 years worth of traffic deaths for the UK, in one go. So yes, we take calculated risks all the time, but the comparison to driving isn't useful IMO.
Smoking isn't a fitting example. You can do whatever you want to yourself in your own home, but it is significantly restricted in public were it effects other people. It's obviously about calculated risk, but that is weighted very different once others are involved.
An interesting other aspect is the change to the status quo. To stick to the better example: Humans accepted that some traffic deaths will happen. But lets imagine that for unknown reason all around the country, car tyres start to just suddenly burst, steering cars into incoming traffic. I'd not be surprised if driving would be restricted until we got to the bottom of such a phenomenon. Even if the average chance of dying on a given day for the average citizen didn't increase manyfold.
Now that I've written that... kind of reminds me of a certain Boeing plane.
[0] https://www.ft.com/content/16764a22-69ca-11ea-a3c9-1fe6fedcc...