It shouldn't be any real surprise really, the odds of you catching COVID in public are extremely small. Add in masks and the risk reduces, add in social distancing and it reduces pretty much to irrelevant levels (think 1 in tens of thousands). It's why the ping test and trace thing is just a complete waste of time.
I'd love to know the positive hit rate between someone who gets pinged and then later goes to test positive themselves. I bet it's lower than 5% (it must be given the huge difference between daily pings and daily cases), and then a massive proportion will be people in the same house or pinged due to being at their mates etc.
If anything most studies seem to point out that we shouldn't need social distancing or masks in public, especially outdoors which is nonsense. If we follow the evidence alone then the only place that we should be wearing masks and social distancing is when we visit other peoples homes but guess what that has never been a rule.