Although I agree Netflix is more at fault here, I think gmail could also make you aware if an email is sent to a non-canonical address. They do have the canoni

Although I agree Netflix is more at fault here, I think gmail could also make you aware if an email is sent to a non-canonical address. They do have the canonical version to compare to, whether that's with dots or without. I also have to put forward that if you have trouble telling people your email address then you probably chose a bad address. You didn't have to put in the dots, and he isn't actually suggesting that they get rid of them now anyway. I point this out only because it means your use case doesn't mean it's an "important and useful feature".