Adding more good content is always better than only trying SEO techniques.
When a single page website, or a blog with only one or two posts, has hundreds of backlinks to it, that will identify it to Google as having paid backlinks and not genuine ones. In that case it will be penalized by Google.
A website or blog with a lot of links leading to it, and not all to the homepage but to individual articles, indicates that people have found something they want to share or recommend. That will allow Google to identify quality content and rank it higher.
When a single page website, or a blog with only one or two posts, has hundreds of backlinks to it, that will identify it to Google as having paid backlinks and not genuine ones. In that case it will be penalized by Google.
A website or blog with a lot of links leading to it, and not all to the homepage but to individual articles, indicates that people have found something they want to share or recommend. That will allow Google to identify quality content and rank it higher.