SEO is of itself is not all bad. Content creators need to do certain things, which do little directly for the consumer, but help the algo understand what the content is and how the owner would prefer it be seen. For example, something simple like the title attribute of a web page tells the search engine how it should label the content in the search results. That's SEO and generaly a good thing for everyone.
As you say, the "please like, subscribe, comment and say a prayer to the algo" annoyance is just what we have to accept for free content on these platforms. It's the cost of anyone being able to upload video to YT.
Where it goes wrong imho, is filling the world with essentially meaningless machine produced content to aid in the rankings. This isn't new with AI btw. People have been using article "spinning" or outsourced garbage content creation for years or decades to do the same and potentially even better than what AI does. In the old days building thousands of links from garbage content to your content in order to have the algo see the links as "votes" for the supposed quality of the content. Those of us who ran forums saw this all the time.