I am sticking with this reprehensible company for email because their spam detection is awesome and I have found no clear measurements of detection to reasonably compare. Iād love to be proven wrong!
Switched from Gmail to Fastmail about 10 years ago.
2-3 spam emails slip through every week, and sometimes a false positive happens when I sign up for something new. I don't see this as a huge problem, and I doubt Gmail is significantly better.
Gmail significantly improved the email spam situation for everyone by aggressively pushing email security standards like DMARC/DKIM/SPF [1]. This came at the cost of basically no longer being able to selfhost your own email server though.
I agree with the other commenter, I use Fastmail and I get very few spam emails, most of which wouldn't have been detected by gmail either because they're basically legitimate looking emails advertising scams. I have a Gmail account I don't use and it seems like it receives about the same amount of spam, if not more.