WordPress is notorious for consuming a lot of resources on the server. Caching plug-in sometimes works, but not with much success. As more and more traffic comes in, the server will be overworked. Serving static files and combined with CDN, greatly increases the performance by a huge amount.
WordPress is a great app for creating beautiful pages. There are many add-ins that can be used to build a beautiful website. But with the ease of use, comes the notoriously power and resource-hungry site. As you build the website and the database grows, the site will get slower and slower over time. To solve that problem, we will use WordPress to build the site, but serve a static version of the site to the general public via a Global CDN service.
Going the route of using a static site, we won't need to use any cache for WordPress. One of the big reasons for not using cache is that cache sometimes gets in the way of reviewing new changes because it's cache old files rather than serving the new files. You can see the obvious problem that it causes by serving old files rather than new. This can cause a lot of frustration when developing a website.
Since we are not building a transactional E-Commerce site, which WordPress is the worst choice for, we don't need to have the dynamic feature of the site. For an E-Commerce solution, other true eCommerce platforms like Magento and others would be more appropriate for that purpose. However, WordPress is great for presenting a digital catalog but it is not to be mistaken for ecommerce. After the pages are created, you can view them before deciding to publish them. Webpage static creator like Simply Static is used to create a static page of the entire website. Doing this greatly improves the user's experience by serving the page to them quickly. This can be done because there is no need to query the database. It can also be made more reliable by hosting the site on a CDN, which is guaranteed to stay up 99.99% of the time and serves the content worldwide.