When I was putting together the Standard Ebooks website[1], I wanted to take cues from the epub books we were producing: having a classic document-centric format without JS, based on traditional, accessible HTML elements, without frameworks, and with an emphasis on semantic structure without <div> soup.
The result is a site that loads almost instantly, whose HTML transfer is small--12kb for the homepage and 24kb for the ebook grid--whose CSS transfer is 10kb, and whose JS transfer is 0. The bulk of the network transfer goes to the initial download of our self-hosted fonts, and cover images. Yet the site looks perfectly modern and even has effects like grids, form effects, transparency, responsive layout, and dark mode. It's hosted on an inexpensive DO droplet and has survived multiple HN hugs without breaking a sweat.
If you're making a website, chances are high that you're just making a document that maybe is a CRUD app. Plain HTML was designed with documents in mind, HTTP/REST was designed with document display and CRUD in mind, and CSS is advanced enough where we can make it all look really nice. Go back to the basics!