Marketing Platform Independence

I'm wondering what patio11's answer is to the passage saying that SEO makes you platform-dependent, in the same way that iPhone apps make you platform-dependent on Apple:

"In my opinion SEO is the same way. It's an ever-shifting landscape of shit you chase without ever really knowing what the rules are. If you're doing SEO as one of ten tactics to get people to show up to your site, that's great. If you're betting the entire business on getting traffic through search results, at any moment a competitor or the platform itself could oust you."