Earlier quoted context omitted.
Sadly, this says more about how broken GMail now is than anything else. Real Soon Now(TM), the tech community needs to start a serious campaign to shame and isolate email providers that do not reliably deliver legitimate emails, regardless of how high profile they are. It probably needs meaningful government/regulator backing to get anywhere. The odd false positive on spam/malware filtering is understandable, it's no…
“the tech community” doesn’t matter: users chose gmail. Shaming them won’t do anything, because the users are the ones whose choices matter.
I have had customers contact my business to ask for help with something, and we send them a quick reply answering their question, and then the next day we get a frustrated follow-up asking why we are ignoring them, and this continues for another round or two until they give up on buying something from us or cancel a subscription.
I have had friends send me a reply a month after a big party saying they're sorry they didn't make it but they only just found the invitation and the follow-up I sent them in their junk folder.
Those sorts of cases are annoying and seem to happen all the time these days, but imagine if a missing email was something really important from your doctor or your kid's school.