I am defining "dumb" as "incapable of determining what url they are visiting and therefore vulnerable to scams". That's a looong way from any sane definition of "expert".
I'd rather my doctor and car mechanic and grocer get to focus on their areas of expertise than have to learn some baroque rules about links in their email.
The problem, of course, is that this trains us to be incapable, and leaves us incapacitated if anything goes wrong. If my rental car breaks down I have no idea what to do except ring the rental company and hope they can send someone to fix it. Likewise, if Google's filter makes a mistake (which it will) then the user has no ability to make any kind of decision on their own. They'll click on the fake bank, lose all their money, and whose responsibility will that be? Google won't pay them back - they just provided a free tool. The bank will want to shift responsibility ("you must have done something unsafe, Google stops all phishing attempts, so you must have told them your login details"). The net result is that while most people will be safer, some people will be in a worse position than they are now.
It doesn't solve any problems for anyone, it just makes us helpless if there is a problem.