No, contents aren't the only thing helping here. Google has its own way of detecting whether your content is beneficial for the keywords you are targeting or not, which means it at-least needs to have backlinks in order to show that your content is getting backlinks from different websites because of how informative it probably is.
DO NOT blindly build backlinks, build relevant ones that are relevant to both keyword & content. On-page SEO is also important, so make sure your home page + posts are well optimized for the keywords you are targeting, this is where backlinks come in; they help your keyword reach a much better position in the search results.