Earlier quoted context omitted.
Absolutely. SEO really is a zero-sum game.
That isn't true. For any particular search, yes, if one site goes down another site will necessarily go up. However, in aggregate, SEO creates value . Think of StackOverflow, for example: the primary mechanism for success isn't taking traffic from ExpertsExchange -- that is just a much-remarked side effect. The primary mechanism for success is successfully incentivizing the creation and distribution of answers for a…
SEO can mean "help make my site easy for google to honestly evaluate and judge the quality of my content" or it can mean "game google into thinking my content is what people want to see even though they probably don't".
I can see how having a better index creates value but I'm not sure how SEO contributes to a better index. It seems like google changed the rules, some companies are doing worse, some are better (zero sum) but hopefully the index is better and people can find what they want (unlocking value). Is that what you're getting at?