I'm not going down the US rabbit hole. Don't care. South Australia would be about the best test case for us.Well almost all of what you've said here is wrong. The first confirmed Covid case in the US was 4 days before the first confirmed Covid case in Australia. Covid was pretty well established in US communities in February and March, which was the same time that cases were starting to rise sharply in Australia. The difference is that the US generally didn't do that much to bring things under control whereas Australia implemented lockdowns and closed international borders, and essentially eradicated the virus. Also, more Americans died from Covid in 2021 than in 2020, despite vaccinations being widely available across the US from very early in 2021.
As for your statement about Omicron, that only holds true for people who are vaccinated, which as has been well covered in this thread is something that you do not want to put any pressure on people to do.