Some times, people have cookies plugin. Those plugins are in the footer or in the top. if is in the footer, some people do not close it, so it makes imposible to find the arrows.
Some people just do not realice about the arrows…
i did test with some people and it was not easy to everybody to find how to change a page.
People askme why not in the wordpress way, after the content (in desktop mode maybe), or the arrows in the side in the mobile, tiny arrows as other books, like the example.