There are still issues (the iterator API used by for(:) is very hard to make safe without terrible perf issues, though I was looking at this recently and the compilers are doing much better than they used to).

Things like unique_ptr and shared_ptr do not meaningfully improve the security of c++ despite being presented as if they did (all serious c++ projects already had smart pointers before the stl finally built them in so presenting them as a security improvement is disingenuous), and because of the desire to have shared_ptr be noninvasive it’s strictly worse than most other shared ownership smart pointers I’ve used.