Well, personally I have to disagree with @Stanley Orchard
in one regard. For a person that is just on YouTube and doing what they love doing and maybe getting some subscribers and all is fine. You are totally correct. But if you're a business, influencer, sell a product or service, or basically are in this whole industry to make money online then social media marketing is fully required.
Because, with the tools I have not including TubeBuddy
I can target the audience that is already looking to buy "judging by what there searching on YouTube, Google, Bing, etc" and direct them to my Shopify, Ecommerce website, etc where I'm selling that particular thing. But "making money" or "ROI MUST
be a serious goal for you because it is not cheap. At a minimum you're looking at a $1,000 a month and that's just for a social media manager, consult or agency to manage all your social media channels. Each site is considered a "channel."