Yes it is built with SiteOrigin builder. Page sections are no longer recommended although still supported. For all those starting to build the site now, we recommend using SiteOrigin.
If you download the latest version of the theme, all the content part of page sections are now available as part of page builder by SiteOrigin. The two home pages have been rebuilt with page builder elements and we have added support for 30+ custom SiteOrigin widgets or page builder elements. If you import the sample data from the latest sample data file, you should see the two home pages built with the page builder.
And the latest version of the theme downloadable from ThemeForest also has documentation regarding how to use SiteOrigin with our theme.