I resisted switching to Fastmail for a long time because I believed Google's spam filtering was best-in-class.
The reality is, for my accounts, I get more spam in gmail than in FastMail.
The reality is, for my accounts, I get more spam in gmail than in FastMail.
About 1 out of 15/20 emails that get flagged are legit. Most are newsletters I signed up to and don't particularly care about, but they're still not spam.