Advertising is absolutely critical to society. Without advertising we can't figure out what companies are selling, because they can't tell us. That puts a real crimp of having a functioning economy.
I don't have statistics handy, but I assure you that if advertising were generally banned there would be a lot less, say, smartphone owners. If you think the average person is capable of figuring out what is available from word of mouth you are grossly overestimating what a normal person is capable of.
> Advertising isn't critical to society, it's mostly a way for a lot of people to waste a lot of time, man-hours and natural resources on zero-sum game
It isn't a zero sum game. It is value add. People can't exchange money for goods and services they want if they can't find a vendor selling said goods and services.