No it isn't rare. The CDC estimates half the spread of COVID is by asymptomatic or presymptomatic carriers that don't know they have the virus.Except there are increasing evidence that this is extremely rare to the point of being insignificant
Household Transmission of SARS-CoV-2
Coronavirus Disease 2019 (COVID-19)
What you posted is spread from inside a household to other household members not how it's getting from one household to another.Masks are primarily intended to reduce the emission of virus-laden droplets (“source control”), which is especially relevant for asymptomatic or presymptomatic infected wearers who feel well and may be unaware of their infectiousness to others, and who are estimated to account for more than 50% of transmissions