If you are manipulating search through SEO you are steering a select few search strings to your pages. For example, you may be running SEO on the phrase "snow tires." That will not impact anyone who is not searching for snow tires. More than that, your motives are immediately transparent to the searcher and the search engine: you are attempting to connect to someone searching for snow tires. If you are manipulating search through algorithmic manipulation you are steering everything. Sure - "most relevant results" yadda yadda. But if autocomplete on "Boeing is" comes out "An American company" on DuckDuckGo and "Doomed" on Google, do you really feel that Google should be able to do that? With 88% marketshare in search? As a publicly-traded company? See, my snow tire SEO guy can't short Goodyear and then do his magic. Boeing? Yeah Boeing can short the shit out of Boeing. Or Bernie Sanders. Or Uyghurs. Or glysophate. Or vaccines.
I guess we have different definitions we are working from, and that's where we are parting ways. A search engine's sole goal is to help the customer find what they are looking for. Search for "snow tires" and get reviews of snow tires, manufacturers of snow tires, and installers of snow tires. SEO's sole goal is to redirect that user's attention towards something possibly related (but probably not) in the effort to derail the user's initial intent. Same as advertising: Distract you from what you are doing, to get you to do something else. Search for "snow tires" and get "ski lift tickets". SEO is the focused practice of derailing high quality search results, and distracting the searcher. As such, any company that tweaks their algorithm to break SEO is someone I consider a friend.