Australia case
You come to Hong Kong to renew your visa. So you have to quarantine in HKG for 14 days, 2-3 days to do the visa, then fly back and then quarantine again for 14 days.
Inducing travel this means you have to block off about 33 days out of your schedule for the pleasure of renewing your visa.
You have to admit this can be a challenge for many people.