Economy

I assume employees already wear a uniform and have a dress code to follow. Everyone that chooses to wear a mask being provided with identical masks continues the uniform look.

The problem is, it should now be the employee's choice. Perhaps the employee thinks they might be coming down with or getting over a cold and feel well enough to work but want to lessen the risk of infecting others should they actually be infectious. Perhaps they are caring for an immunocompromised friend or family member, or have a big event in the near future and want to lesson their own risk of getting ill.

With air quality issues from particulates from forest fires, people at risk with breathing issues where I live have been advised to wear masks for going outside. We will continue to see people wearing masks in public.
Though I do understand communication between employee and customer is sometimes difficult when wearing a mask (I work retail), I don't think the company should be able to ban/restrict the wearing of masks worn to lessen possibility of virus transmission.