Too much
C++ seems to have become a melting pot for every idea from every other software language in the known universe. Every year yet another update e arrives with yet another idea or ten. You can't efficiently shield programmers from making mistakes, sometimes serious ones. The extra code required to shield someone from using freed memory is non trivial and just makes software slower. The use of static analysis should be top of the list for serious engineers, work out whether your code is right at the time of writing don't try and prevent it going wrong when running .. at best it will cause an error for the user when you haven't tested the flow through the broken part, God knows what will happen when it is caught. The language is far too complex now