[throwaway3neu94]

In addition to all the points that article makes, two more:

1. There are a lot of people that believe they already had Covid, but actually didn't.

2. A "vaccinated or recovered" policy is even harder to enforce, as there are vaccination certificates but no recovery certificates. (Yes, vaccination certificates can be faked, but it seems likely to me that a significant part of the population would be willing to lie but not falsify documents.)

[throwawayboise]

There are tests for both presence of antibodies (quick and cheap, you can get one at many pharmacies or quick-care clinics) and T-cell immununity (IDK the cost or availabilty of those).