Depending on the license. If you have a CC-BY-SA or public domain at the bottom, then you're allowing people a legal right to keep a copy.

In practice, the nature of the web allows everyone to keep copies of everything if they want. But if someone republishes it, then you need to use the DMCA process (for American websites) to take that content down if it violates copyright.

Going back to print, what if you print something you don't want out there anymore? Well if people have already bought your book or magazine, they have bought a right to that physical copy. They can even sell the book or magazine to anyone else (granted that the content isn't illegal).

But they can't make copies of their bought copy and distribute those, which is akin to what the Internet Archive does.

That's not the point. The OP mentioned he wanted to make sure nobody can read it anymore. Private copies prevent that scenario.