My laundry detergent is always advertising that they have a new improved formula to get me the cleanest clothes. My gasoline brand for my car tells me all the time how many more miles per gallon I get from them. And who knows how incredibly healthy I'd be if I took all the stuff they advertise to improve my health.
Why will chain oil be that much different in their advertising?
But to be fair, there are newer (within the last 10 or so years) formulations that seem to work better to keep my chain less gunky. I don't wear chains out very fast, so lubrication differences aren't a concern for me.