The point is that you can get some safety guarantees. Nowhere near the degree of guarantees available in safer languages, but still better than the status quo.
Edit: one example of a pattern, whose name I can't remember, was to switch from returning pointers to data structures, to returning pointer offsets as handles. Using these handles you can then track more information about validity and handle "null pointers" more sensibly rather than it introducing undefined behaviour. In superscalar processors the offset calculation basically costs nothing, but the additional safety can be considerable. I believe I read about this pattern in game engines, let me know if you know the name of it!
You can get some safety guarantees. Many of these things are very good choices. I own a very large C++ codebase that uses this approach you mention all over the place.
But you can still see important limitations. Chrome, for example, has custom smart pointers (miracle_ptr) and still has UAFs galore.
