They actually started certifying venues for air exchange rate early on in the pandemic, there's hand sanitizer pretty much at every shop, everyone wears a mask, plexi panels and other barriers are common, people get told to check their body temperature and not attend events if >37.5, many places actually have thermal cameras or other measurement devices at the entrance, etc.

Add the vaccination rate to all that and it's not hard to see how the R number dropped to <1 (and stayed there). Though we may be rebounding slightly in the last few days, so we'll see whether it's the start of a new wave or not. Whether we get a significant year end wave like we did last year will tell the story.