Masks are one of a range of options. Here in Australia, masks were never compulsory or even strongly recommended and if you go out on the street it would be only about 1 in 50 wearing a mask, and they would be predominately Asians who would have been used to wearing them pre COVID-19 anyway.
What we did here which was our effective measure was encouraging everyone to stay at home as much as possible, shutdown pubs and restaurants and enforce social distancing everywhere.
The other factor was of course that we reacted early.
