I'm not sure how commonly shared this sentiment is, but as a consumer/subscriber to many channels, I feel that the new changes could dramatically impact my user experience of watching content.
I'd hate to miss out on videos I subscribed to, and I'd probably resort to making my own subscriptions feed: setting up a script to scrape my favorite channels, and compiling a list of new videos. I'd probably end up discovering far fewer videos that I am not subscribed to.
there are still factors to focus on other than just writing honest and good content though. Google makes it clear about weighing results based on mobile-friendliness, for example, and it's worth at least looking at Google's guidelines to make sure there aren't low hanging fruits of honest site-improvements that will bring SEO benefits