The Guardian website, whilst not perfect according to the standards of the article and some other posts, is very performant. They have ads and other dynamic content, but load is deferred on this stuff and wrapped properly to avoid reflow, so the entirety of the article text is immediately readable. Just for interest, see also their tech blog [0] and their entire frontend on GitHub [1].

I can ignore ads, but what I find incredible on major (insert news/tech/whatever here) sites is the reflow from not properly reserving space for both ads and lazyloaded images. The following seems particularly to be a problem on mobile and in apps like Apple News: load a page, scroll to the meat of the article, then experience 1, 2, 3 page jumps as stuff loads in above your scroll position.

[0] https://www.theguardian.com/info/series/digital-blog [1] https://github.com/guardian/frontend