Making your content discoverable matters because it's how you get more relevant users viewing your content. If a search engine has trouble seeing your page, you're possibly missing out on a source of traffic.
By making sure search engines can find and automatically understand your content, you are improving the visibility of your site for relevant searches. This is called SEO, or search engine optimization, which can result in more interested users coming to your site. Audit your site and check the SEO results to see how well search engines can surface your content.