You don't even need to do a certain aesthetic to make your website fast. Just send your entire content in the HTML, instead of needing extra HTTP requests for JS and then more HTML before having all the stuff for your first render.
The early internet aesthetic is why, as much as I dislike the site's culture, I continue to use reddit + RES.
The UI, the minimal buttons, the tight paddings, the lack of pop-in, the complete lack of animations; these have all been essentially unchanged for the past decade. Even the dark mode colors look exactly as it did the first time I switched it on.