This is a site that has, more or less, the same functionality as my blog I imagine that you're asking why this page exists when a normal version can be found at benyakiredits.com.
This website's powered by GatsbyJS. It may not mean much to you, but there are a few reasons why this is valuable. Gatsby uses React, which is a single page application. Normally, when you visit a website, your computer sends a request to a server that processes the request then sends information back. On my WordPress blog, every time you visit a new page, the server processes the request, generates the page based on the pages and posts then sends back information. React, on the other hand, doesn't do this. Your computer sends only one request. It sends back one package that contains everything. Gatsby is a little addition that has a few extra features to allow search engine optimization and the use of GraphQL.
First thing you can notice is that each section zooms out and does something instead of having to load an entirely new page. Also the sidebar stays open no matter what page you visit. This is possible because of React. Or, rather, it's facilitated by React. It wouldn't be easy with just WordPress, and having a second site with its own routing and data management makes it easier. Gatsby makes that a cinch in a bunch of complicated ways I don't want to explain right now.