In the first weeks of Corona's "official" entry to the US in 2020 (1), it was reported that sick people in the NY area had to pull strings or prove contact with a known patient or recent travel to an infected area to get tested when calling the official hotline.

So nobody who caught it on a train or in an office could confirm if they needed to quarantine, which actually happened.

If that person was later admitted to a hospital, it was game over for that hospital and any elderly people sent back to their nursing home.

1. The actual entry date was likely fall 2019 because of the Wuhan Military Games and airline travel from China to the US. SF never really had a hospitalization spike in 2020, so corona infection appears to have been spread out compared to other cities and was probably endemic in 2020.