Who says it is safe? Barm pots!
Nothing can ever be completely safe - you take a risk walking to the bottom of your own garden. A meteor might drop out of the sky and land on your head, for example.
All you can do is minimise risk to as low as reasonably practicable.
Our favourite pub/restaurant posted on facebook to say they will be opening on Saturday. They have created an outdoor kitchen, you have to order your food in advance, and they have put tables, spaced out, in the car park. There is no indoor seating. You can either take your food home, or eat it at one of their tables, but you have to book a table in advance.
That seems eminently sensible to me, and given that there small number of cases locally is declining even further, it's a risk I'd be prepared to take, except that the weather forecast for the weekend is cold and rainy.
But I applaud them for doing the best they can to keep their clientele and staff safe & we'll be up there before too long.
If it was somewhere where cases were rising I'd feel rather differently.