Boosting our web utility's SEO?

Hey everyone, I'm hoping to tap into the collective wisdom here regarding a persistent challenge we're facing with our web tool, the 'Country Codes Directory'. It's a straightforward but incredibly useful resource for international phone, calling, dialing, and ISO codes. We've seen decent usage and positive feedback, which is great, but we're really struggling to gain traction with organic search traffic, and that's the pain point right now. Our current situation is a bit frustrating because, despite the clear utility of the tool, our organic search visibility is quite low. We get a fair amount of direct and referral traffic, which tells me people find it valuable once they discover it, but we're just not showing up for many of the relevant keywords we'd expect. It feels like we're missing out on a huge chunk of potential users who are actively searching for exactly what we offer. We've tried a few basic SEO steps, of course. We've optimized meta titles and descriptions for key pages, ensured the site is fully mobile-responsive (which it definitely is), and even created some related blog content, things like 'How to call X from Y' guides. While these efforts have been good practice, they haven't really moved the needle significantly in terms of organic gains, and our rankings for core country code searches remain stubbornly low. I'm hypothesizing a few reasons for this struggle. One major factor could be the intense competition from established giants like Wikipedia and various government or telecom sites that naturally rank for this kind of data. Another might be the niche nature of the data itself, or perhaps there's an inherent difficulty in ranking a pure reference 'web utility' like ours that doesn't have a lot of 'blog post' type content. It's a directory, after all, and the content is mostly structured data. So, I'm really looking for some specific, actionable strategies for driving organic traffic to a data-heavy reference tool like this. Has anyone here had success with advanced SEO techniques beyond the basics for similar projects? Are there content strategies that work well for directories that aren't just endless blog posts? What about link-building tactics that don't feel spammy but actually generate authority? Any unique approaches that have worked for your 'web utility' projects would be incredibly helpful. Thanks in advance for any insights or advice you can offer!