They may be wearing full PPE but are by definition in daily contact with patients affected by a highly contagious virus. Pilots (especially flying freight) only share a flight deck with other pilots (who follow the same strict protocols and are tested at least once a week as well). No cabin crew, no passengers (what are those again?)
Interaction with people in other countries is minimal as we’re confined to our rooms, the crew transport is supposedly disinfected and we of course wear masks during the airplane-hotel transit. Home, cockpit, hotel room confinement, cockpit, testing on arrival, isolation until test result comes back negative. Rinse and repeat.
Recognising that medical professionals are precious at this time, they are allowed to return home after a shift despite a certain amount of risk to the public, and rightly so; they are critical at this juncture and their mental health must also be taken unto account.
Assuming we are also necessary to move goods, medical gear, reagents and vaccines into and out of Hong Kong then we should be treated similarly. Of course no-one says medical personnel shouldn’t be allowed to go home, but then why can’t we? Objectively the risk is higher for those treating Covid patients.