Again, Iains, you quote all those numbers without saying how common they are in the general population

There are a few things going on there.
1) how likely are you to contract COVID-19? - social distancing apart (pun intended) - it is no respecter of status, be careful!
2) If you can't be careful, be lucky
3) If you can't be careful, have a healthy/lucky lifestyle.
4) If you can't be careful, be young (I am working on that one)
5) Some of the people we rely on like doctors and nurses (+ police, firemen etc) may be vulnerable yet answer the call. And pay the price. It has happened.