USA only requires that for air passengers. Requiring overseas checkin agents to be disease doctors was okay, but asking CBP to verify paperwork and stop threats at the border was too much to ask.
Funny story I heard recently: Someone tested positive in Mexico but "had to" get home. Flew to Tijuana, walked across the border (no COVID test needed for land crossing), and caught a flight home out of San Diego.
It still makes sense to protect the airline employees, but I no longer view a pre-flight test as a reliable measure to stop COVID from arriving in the US.
