Magento 2.3 PWA Studio was released in order to support merchants to convert their websites to PWA. In other words, it provides a set of tools for developers to develop and deploy PWA storefront for Magento 2.3.x websites.
However, the Magento 2 PWA demo created from Magento PWA Studio is immensely basic, you check it at https://veniapwa.com/. As you can see, it does not provide all default features of Magento 2. There are no header, homepage (banner, new products/ featured products block), category page (layer navigation, comparison sidebar, sort by), product page (add to wish list/compare, products attributes), my account page, customer login, as well as some PWA features.
On the contrary, Magento 2 PWA Theme, developed by Tigren, not only offers full PWA features but also fulfills all fundamental of Magento e-commerce websites. As a result, it’s okay if you want to use the default Magento 2 PWA Studio tools, but there will be a long way to go. Or, you can apply our ready-made PWA theme to convert your site to PWA quickly and effectively.