Works pretty well, if any of those addresses gets into some spam list I just block it (hasn't happened yet, though)
Grey listing has been far more effective at stopping spam than some half-baked AI garbage from Google.
Grey listing doesn't scale; not for me.
Which is more than the non spam emails that come on it :)
Next time a legit email ends up in your spam folder, use this tool to figure out why: https://mxtoolbox.com/EmailHeaders.aspx
I've had a few cases myself, and it's always been the sender's fault.
With Gmail, you can configure an external SMTP server using "Send mail as" setting. Super convenient. Tons of mail services offer a generous free tier for personal use (e.g., Mailgun 100 emails/day).
It's not really worth paying just to send a few personal emails from @yourdomain.com each month.
Just joking, I expect nothing from GMail team after I noticed that "block sender" option just puts emails in spam folder instead of deleting them on arrival.
I have accounts on Gmail and other services, and can say from close to a decade of use that Fastmail's spam filter is usually far better than Gmail's.
Occasionally it'll fall behind for a few weeks, but always seems to catch up or surpass Google's.
Over the last couple of months, for example, 100% of the spam I've received has come from Gmail. 0% from Fastmail.