I totally agree that we are at times paranoid when it comes to our dear ones. I myself have reacted like that many a times with my dad and MIL despite living in the same city. But what we need to ensure is that they take proper care and maintain social distance when they happen to go out. An occasional outing with required care should not be an issue. But it’s always better to restrict socialising to the minimal.
They need to make sure of wearing preferably a surgical 3 layer mask that protects them and dispose it appropriately by snipping or burning them after a group gathering. They need to leave or come out in open far away from crowds to avoid direct exposure and also make sure that they happen to touch minimum surfaces. Once they come home, it’s better to put their clothes for wash and also have a head to toe shower as a precautionary measure.
It’s always better to suggest/insist on precautionary measures rather than imposing a blanket ban on them. Today it is Covid pandemic, tomorrow it may be something else. How long will we keep the family locked down at home. It’s better to guide them to take care responsibly and appropriately when they step out and also insist that they do not binge on the freedom and end up missing out on precautions occassionally.
Just like NO is not a solution for handling kids, it applies to elders also. Think back and see how they handled our resistance many times even if they strongly felt that it was not right for us to indulge in that particular act.
Hope this helps bring clarity to you.