Yes, but there's hope. Making safety opt-in is a necessary prerequisite of backwards compatibility. Enforcing the use of safety annotations, however, is something that linters can enforce, and every major C++ codebase uses one form of another of supererogatory checking. By enforcing safety via linter, we've transitioned a robustness problem to an ergonomic one. Specifying "safe" over and over is hideous, aesthetically.

I think C++ needs a broader "resyntaxing" --- something like what Elixer is to Erlang and Reason is to OCaml. Such a resyntaxing wouldn't change language semantics, but it would allow us to adopt new defaults --- ones that benefit from decades of hindsight. A C++ Elixer wouldn't only mark functions safe by default, but would probably make variables const by default too. And it would be 100% compatible with today's C++, since it would be the same language, merely spelled differently.