WordPress themes are responsible for the structure and strength of any websites. The file you'll receive when you purchase the premium plan is actually a plugin, and needs to be installed in your site's plugins folder. But for others, if you're willing to spend some time to create something truly unique then GeneratePress is for you. Even as you change themes, you'll still be able to retain your designs.
It does not offer a Pro version per se (as GeneratePress and Astra do), but paid extensions that allow you to add features to your free theme (e.g. adding modules to Elementor with the Elementor Widgets extension, creating a Portfolio with the Portfolio extension, a sticky header with the Sticky Header extension etc.).
In recent time page builder for WordPress makes the work much more handful for the developers. Gridsby is a free photo-blogging WordPress theme designed and hand-made for photographers. Thrive Themes is the latest hot themes club in the WordPress community. Unlike the other themes in this article, Skin is a completely free (and fast loading) WordPress theme.
Only when you are importing demo content from GeneratePress you will need to disable it. GeneratePress is just one of the themes working very well with Elementor. Monaco is a premium multi-concept WordPress theme with a vintage style. The depth of these options goes way beyond GeneratePress demo site what most regular WordPress themes offer.
Although Genesis has lots of stunning WordPress themes, they're nothing compared to GeneratePress. This theme is really a great choice but only when you are utilizing Elementor professional's theme builder to create your whole site. Brook offers a diverse and colorful collection of demo sites that can be used for business owners, freelancers, and eCommerce stores.
In my experience, if you find a great multipurpose theme that you know you're going to use more than once, the best bargain is to get a lifetime license for unlimited websites. Organization of these options is better in Astra theme as compared to OceanWP. The theme also has layout controls which are a bit limited as most of the options are only available in the premium version.