The thing about chickenpox, though, is that when a kid gets chickenpox, there are often deliberate efforts to get other children in the neighborhood infected at a young age so that immunity is robust enough to handle the infection (whereas an adult will end up with a much worse case of shingles). So its R0 is inflated.
Now, consider COVID. Instead, when you deal with COVID, they immediately isolate you and anyone you've contacted for 10 days. So, there's a much higher POTENTIAL R0, but it's blunted by all the measures that they've done to try and stop it. The original strain was originally an R0 estimated in the 2s--but that was based on only 1 in 6 being contagious, and that one superspreading it. So is it any more contagious than it was, or are all the social distancing measures just collapsing under their own weight? I think it's the latter. It was always super-contagious, just beyond our ability to control it long-term.
