Hi ArthurRadtke,
In theory, a well-coded and optimized HTML site will perform as well as pages from a well-designed CMS site in organic search rankings.
Some of the most important HTML elements to achieve SEO success.
HTML title tag: They have always been and remain the most important HTML signal that search engines use to understand what a page is about. Bad titles on your pages are like having bad book titles.
Meta Description tag: If the HTML title is the equivalent to a book title, the meta description is like the blurb on the back describing the book.
Header tags: Header tags are a formal way to identify key sections of a web page.
Structured Data: The result of structured data often translates into what is called a ‘rich snippet‘
Hope it helps you.