CMS systems like WordPress allow for easier updates and maintenance of dynamic websites compared to static HTML sites, as content can be edited directly in a web-based interface without coding knowledge. However, static sites can sometimes have advantages for SEO as pages are typically lighter and load faster, avoiding the potential for bugs, downtime or slow performance that a CMS may introduce. Overall, either a CMS or static HTML can work well for SEO depending on the specific needs and resources of the individual site.