In my opinion developing in XML/HTML for GitHub Pages isn't as easy as using Wordpress. The challenges for a new learner are also the challenges faced when modifying the layout of the site. This problem is the required knowledge of XML/HTML coding. In order to develop my GitHub page I had to learn how to code the layout of the website to my specifications. However, there is an advantage with developing using XML/HTML that those with coding experience can take advantage of. That advantage being the amount of control over the design of the website. Using code, a developer can be much more thorough and in depth with website design and adjustment.
On the other hand, using Wordpress is much more simple for everything. New users should find it easy to add pages and other things in order to craft their website. I think the ease of use is where the advantage of Wordpress lies. Let's say a website is a pie, coding in HTML would be like making the whole thing from scratch, while Wordpress is like buying premade pie crust and filling from the store. Wordpress gives premade options, and has a user friendly UI to help with website development. However, since options are given to the user, they don't have as much in depth control over adjustments they want to make with the website.