My experience is the exact opposite of yours - I find Gmail's spam detection absolutely amazing. I get essentially zero spam in my inbox, and perhaps 4-6 false positives in the spam folder a month.
>As a Gmail user, there is nothing you can do to verify that you're getting all of the legitimate mail traffic that is being sent to you.
What other communication service/protocol would allow you to do this?
That's 4-6 valid messages a month the average user will never see.
Ideally this phrase would not be so widely known and understood if Gmail didn’t have so many false positives going to the spam folder. I’d imagine that, as a performance metric, the Gmail team would consider false positives to be a metric for improvement, not a metric of pride.
Because of that I just added a recurring remainder to go through gmails spam folder every sunday, but that of course defeats the purpose.
Gmail also thinks that every 2fa message from Microsoft is spam for some reason, despite how often I tell it is is not.
Low and behold there was an email in there that was fairly important.
That seems like a lot; with FastMail I get basically 0. The last time this happened was years ago.
I do get the very occasional spam, maybe 5 messages/month or so. Most of them are from marketing agencies that want to "collaborate" on my website or some such and have a spam score of 0 or close to it, and arguably isn't "spam" in the same way as "grow a bigger dick!"-spam is. I doubt gmail would catch those too.