By 2025, on-page SEO will be more about ensuring content and structure of the site are optimized in addition to keywords, user experience whereas off-page will have more attention on authority through backlinks, social signals and brand mentioning. They are necessary both, because, on-page makes sure your site is search-engine friendly, and, off-page increases credibility and ranks because it was validated and engaged by other people sitting outside. https://blogs.sparkifysolution....s.com/on-page-vs-off