I remember hearing from an ER MD that even if you can be revived after cardiac arrests, the outcomes aren’t amazing. You’re very likely to end up with serious brain damage and mich lower quality of life. I don’t remember the exact numbers but it was something like circulation has to be restored within 4 minutes or something to suffer little damage. Paramedics probably can’t even attend the scene within 4 minutes let alone start reviving. His point was that having a DNR makes a lot of sense even if you’re healthy and it was explaining why he chose to have one.
In that context it might make sense to stop reviving cardiac arrests altogether, pandemic or not.