Why is Transport Canada still requiring the wearing of masks in airports and on board flights to, from and within Canada, while some provinces are removing this requirement?

Although the epidemiological situation is improving domestically, in general public health authorities continue to recommend the wearing of a non-medical face mask to protect others around us from the spread of COVID-19, especially in situations where physical distancing is hard to maintain (such as seated on an aircraft, customs hall or during a physical screening process).