A lot of people will be interested in the ads and other signs of the times.

Besides, who knows how long theonion.com will stay up. Or keeps giving access to all old articles?

After all, they've just been bought. Usually this results in changes, despite new owner's loud promises that nothing will change.

You're never quite sure what you're actually looking at on the web.

Was this edited at any point after the listed publish date? Did it survive intact during the backend migrations since? Is that formatting supposed to be a bit weird? Is there originally supposed to be an image after that oddly placed paragraph break?

What did it look like back when `<blink>` and `<marquee>` were still a thing? Did it look better at 800x600? Did it show the same page to all user-agents?

Hard copies, physical reality (or at least rasters), are still the ultimate form of immutability.