I just got 78% SEO Score on my Beehiiv newsletter and I've a question

For context: I got this score for my newsletter (solocodeventure.com), I built it using beehiiv and got this result. All the ideas I share (my newsletter is about weekly SaaS Business ideas developers can build) are available online and can be searched. I know nothing about SEO so I'm sorry if my question is dumb but do I have to optimize the ideas and articles somehow to have them perform better or is it up to beehiiv in my case? All I do is write the meta titles and descriptions. Am I missing something? Thank you in advance for your help!