Originally Posted by nomiiiii

2) No medical tests on arrival or departure of the flight - if there are medical tests, that runs the risk of you failing the test. Failing the test means, at best, your non-refundable holiday is ruined if you failed the test before leaving for your trip. But at worst, it could mean disaster if you failed the test say, at the flight back at the end of your holiday and are now denied boarding on the flight back home and unable to go back home to restart your job which risks losing your job.

Same as how visas and passports are fully arranged several days before the trip even starts (and then the visa/passport has to be valid for a few weeks/months so your entire trip is covered), any health tests/checks need to be several days before the trip even starts (so you can cancel and make other arrangements if you're unable to acquire the health certification), and that certification will need to be valid for the entirety of the trip for a few weeks because no one wants to risk being stranded abroad on failing the test when heading back home.