It's increasingly evident that mask wearing that reduces transmission
It does, but does it really have any appreciable impact on transmission in the locations such as shops?... In all my visits, encounters with other customers have been very brief and socially distanced apart from possibly a split second where we might be than 2m apart. The chances of transmission, even if I encountered someone who was infected would be tiny, and given there are only a couple of confirmed infections per week in my 250,000 population district, the risk becomes infinitesimal.
Covid infections overwhelmingly occur when people interact at close quarters indoors for extended periods. In such circumstances, masks would make a difference.... so it makes good sense to wear a mask on crowded public transport or at a hairdressers.
However, I think mask wearing in shops would likely only have a very marginal impact on actual infections, and a like the risks of not washing your shopping in this respect... However, I’d still be in favour of making them mandatory to increase confidence in those more at risk, both helping them re-engage with society whilst also helping to improve the economy. It also would help remind people they are still living in a pandemic and remain aware and cautious.