Nextjs gives you some nice file size metrics when you build your project. Your file sizes should ideally be in the green like around 150k or smaller or somewhere around there.

Also, next has a come a long way with many improvements with things such as next/dynamic and the new app router that utilizes React server components. I encourage you to try out these techniques to speed up your project before issuing your indictment of Nextjs. Frameworks do not alleviate your need to be a good programmer and write efficient code. Think about libraries you could do without and write your own. Try to separate your pages into critical content and components that can be lazy loaded. Think about tree shaking, etc. Nextjs is renowned for its speed so an indictment of being inherently slow is nonsense. Of course, nothing is as fast and efficient as pure HTML/CSS/JS but could you imagine developing a complex PWA using vanilla JS?! Not a bad idea for smaller businesses and portfolio sites though. My blog site is pure HTML and JS . I use webpack to compile my JS and Tailwind for CSS but that’s it. All my pages are static generated HTML from PHP code I wrote myself. My old blog site was Nextjs based and it was slow as hell, but that was because of my own lack of knowledge when I built it. I decided to do my redesign in vanilla because i wanted my blog to be simple and super fast. I chose the correct tools for the job.