This is a convenience sample no doubt, but convenience is important here, as timeliness is important. It is easy to naysay, but why don't you suggest a less bia

This is a convenience sample no doubt, but convenience is important here, as timeliness is important. It is easy to naysay, but why don't you suggest a less biased convenience sample? Because unless you mandate whole population testing, samples will always be biased in some way. Those who have phones, those who have time, those who are motivated, etc etc. Given all the potential ways it could be biased, choosing a convenience sample at locations almost universally used is not bad at all, imo