ASAN has not been successful at eliminating (sometimes exploitable) use after free bugs in the wild. For example, look at this year's Pwn2Own. All browsers are heavily unit tested, fuzzed, and run through tools like ASAN, in addition to making heavy use of smart pointers, and they all fell to UAF.
There is a reasonable argument to be made that memory safety problems don't happen enough to be worth eliminating in practice (though people are often reluctant to make this argument so explicitly). But I don't think it's possible to successfully argue that they can be eliminated at reasonable cost in C++ with the tools we have today.
There is a reasonable argument to be made that memory safety problems don't happen enough to be worth eliminating in practice (though people are often reluctant to make this argument so explicitly). But I don't think it's possible to successfully argue that they can be eliminated at reasonable cost in C++ with the tools we have today.