And it allows me to dynamically "fetch" my writings as I add more. I don't have to create a whole new html file. I simply write a markdown file, add it into the repo on github (I use slackedit which syncs directly to the github repo), then the website gets rebuilt with HTML, and then deployed.
Making the code base more maintainable and better suited for my purposes.
On the other hand, I do agree with you. React is a bit heavy weight for a static website. Next.js still ships the whole react bundle in production. So, while time to first paint is the same speed as a simple html, js site, the time to interaction is much slower and the network load higher.
Trade-offs for sure.