There's also the component of "there are millions of lines of existing C and C++ that continue to exist and the majority of new 'safe' languages are not designe

There's also the component of "there are millions of lines of existing C and C++ that continue to exist and the majority of new 'safe' languages are not designed to support gradual adoption/replacement". So you get gradual improvements to C++ that ostensibly make correct code easier (lets ignore string_view, etc) but no real path to actual safety without just rewriting everything all at once, which is an approach with a long and illustrious history of failure and major regressions even in "successful" attempts.