Why not?
This might be a worthwile tradeoff to quickly build a highly interactive realtime interface. But for a newspaper? As a user I would be very much turned off to endure all that just to read an article.
If the user is on any hardware from the past 7 years, a React developer would have to do some distinctly bad programming to make it behave sludgy. Any poor performance is likely to be from the same things that make a classic static page slow: large media files and tracking scripts.
As a sidenode, it does feel sludgy:
- Scroll is not smooth.
- It does not adapt well to different browser sizes
- After a few seconds the page "jumps down"
But the reason might simply be the overkill of JS,animations, overlapping elements (like the static header), ads, dynamically loaded stuff and other crap. When I turn off JS, some of the problems go away.
A lot of this "JS is slow, what happened to good old HTML and CSS, get off my lawn" stuff is simply confirmation bias.
You could even write an entirely server-rendered web application, or a static website, in React should you be so inclined. In fact, I do the latter for my (very simple) personal site at https://davnicwil.com!
Nothing about React obliges you to do client rendering, a SPA app, or anything complex at all. It's, at the end of the day, just a view rendering library.