I agree, but there are all kinds of scenarios where you might need to simply answer a question - “is this an email address, and does it look valid?”. I needed

I agree, but there are all kinds of scenarios where you might need to simply answer a question - “is this an email address, and does it look valid?”. I needed to do just that once - I was given a flat file with some bulk export data that came from some other system that I had no exposure to and needed to clean up contact data by figuring out what was what, separating names from phone numbers, from postal addresses, from emails, etc. It just needed some rate of success, not to be perfect. Lets not assume that we always know what people are trying to do and what is the best way to do it. Devil is in the details.