You are mistaken about what R0 means. It is a compound number that describes a virus and its ability to spread from person to person in a community, with all the measures (or lack thereof) including vaccinations in place.

The 6-7 range would be in a theoretical environment where nobody is vaccinated, there are absolutely no countermeasures and the number of opportunities to spread is equivalent to the pre-COVID days. Obviously, we do not live in that world.

In short, R0 is not a property of a particular virus strain but of the sum total of virus + all factors relating to population, behavior etc.

It is also best determined afterwards the way it is being treated right now as though it is some kind of input variable which can be controlled for is fundamentally wrong.

I understand what R0 means perfectly well. Vaccination and other factors can reduce it from the 6-7 level to something a bit lower. But there is no plausible sum of factors that will bring it below 1 for an extended period any time soon. Most interventions are correlated, not independent, and so the sum is less than the parts.