The mass testing story is not what you think it is. The tests are optional, self administered, self reported, only available to staff (not students) in many cases and have a 50% false negative rate.
That's rubbish. My kids are stuff swabs up their nose twice a week - and they are lateral flow tests, so we sit there waiting to see whether the double line appears.
https://www.gov.uk/guidance/rapid-lateral-flow-testing-for-h...
It may well be they're telling the truth about their school, but that still makes a blanket claim, like the one made above, misinformation when it's presented with no qualification to indicate it's based purely on an anecdote (I'll note the comment has since been edited to water down the original claim)
Also, the false negative rate isn't a big problem IMO. The PCR 'false negative' rate is far far higher because we are only doing a few hundred thousand a day, so 90% of people are getting missed entirely. I'd rather a 50% false negative rate than a 89% false negative rate from PCR.
There is also the problem that PCR takes at least a day to turn around as well - which will result in more spread.
I'm not saying we should get rid of PCR testing and just do LFD but doing both is probably the best option.