BTW, I also have a problem with this statement from other SEO's, "And we all know that quality content earns links. So rather than hiring SEO company, it is better to spend our money for hiring resources those can create the better content that will earn links."

If you're a large recognizable brand, or if you're industry is "sexy," as I like to call it, than you're not entirely wrong. However, there are so many businesses, especially local business, that don't have the luxury of "build it, and links will come." No, you need reach to be able to do that. For example, I know some SEO's on here have done work for Carpet Cleaning companies. There is nothing sexy about this at all. Realistically, do you think they're going to be able to get very many followers on their social media pages? What kind of content can they build, and naturally get links, without having to do some outreach?

This idea that all you have to do is build good content is BS. It's not a one size fits all - not even close.