The last couple of websites I've made have been largely the output of Claude with some instructions to keep to WCAG AAA accessibility standards and to optimize for loading and rendering times, and it's done a pretty decent job. If you're insistent about page weight it will avoid adding JS and React and use to browser-native elements, CSS, and vanilla JS where it can.

I think the problem is that you have to ask, and to know the language to get the result you're after. If you just ask for a pretty website you're getting 800KB of React libraries to render something, and all in AI Beige with Inter as your font choice.

Do you really need to know the language or is it enough to bother asking about improving the loading time or customizing the look?