Gmail zero inbox
I think that it is now impossible to achieve a zero inbox with Gmail. It's impossible to search on a Gmail inbox according to whether the mails have a folder/label. So as long as I have mail in my folders, I will never have the satisfaction of seeing my inbox empty.
That's pretty stressful, I think you'd agree.
It used to be a big deal on the Web. There was a lot of activity on the Web in the years up to 2009 of people complaining about it. But nobody seems to care any more. I think we should care!