At some airports (not CZM when I was there in Oct), you can get a rapid antigen test on-site, with results in 30 minutes.
As a passenger, faced with the prospect of being hurled through the sky, sealed inside a tin can for hours while seated close to hundreds of other coughing, breathing, talking cattle, I would be strongly in favor of antigen tests for everyone (including crew) done in the airport, as part of the check-in process. Include the cost in the ticket, eliminate any falsified test results, eliminate the stress of finding a time & place to get tested in advance, etc.