For C/C++, memory safety is a retrofit to a language never designed for it.
Many people, including me, have tried to improve the safety of C/C++ without breaking existing code. It's a painful thing to attempt. It doesn't seem to be possible to do it perfectly. Sutter is taking yet another crack at that problem, hoping to save C/C++ from becoming obsolete, or at least disfavored. Read his own words to see where he's coming from and where he is trying to go.
Any new language should be memory safe. Most of them since Java have been.
The trouble with thinking about this in terms of "95% safe" is that attackers are not random. They can aim at the 5%.
The most popular ones have not been necessarily. Notably Go, Zig, and Swift are not fully memory safe (I’ve heard this may have changed recently for swift).
Go's memory safety blows up under concurrency. Non-trivial data races are Undefined Behaviour in Go, violating all safety considertions including memory safety.
I would not expect that it makes sense to provide this as the default for Go's hash table type, my understanding is that modern Go has at least a best effort "fail immediately" detector for this particular case, so when you've screwed this up your code will exit, reporting the bug, in production and I guess you can curse "stupid" Go for not allowing you to write nonsense if you like, or you could use the right tool for the job.
For C/C++, memory safety is a retrofit to a language never designed for it. Many people, including me, have tried to improve the safety of C/C++ without breaking existing code. It's a painful thing to attempt. It doesn't seem to be possible to do it perfectly. Sutter is taking yet another crack at that problem, hoping to save C/C++ from becoming obsolete, or at least disfavored. Read his own words to see where he's coming from and where he is trying to go.
Any new language should be memory safe. Most of them since Java have been.
The trouble with thinking about this in terms of "95% safe" is that attackers are not random. They can aim at the 5%.
[1] https://herbsutter.com/2024/03/11/safety-in-context/