This particular thread of discussion had its origin here:
Our culture will survive for a few more months without large mass gatherings. And if we play our cards right, it may well only be a few months, if that.
And I believe that part of playing our cards right is to allow herd immunity to gradually build up to a level where mass gatherings aren't an issue anymore.
This means, for example, letting kids play with each other, and gradually encouraging businesses to re-open in a strategic manner.