People in NSW urged to wear face masks as community transmission grows

Why has it taken so long for authorities to even start ‘urging’ people to wear face masks? Could some of the community transmission, especially where people have been infected in public places, have been avoided if everyone had been wearing face masks even if they had ignored social distancing guidelines?
Health authorities in New South Wales are urging people to start wearing face masks in a range of scenarios, as community transmission of COVID-19 grows.