borrowck is a semantic check. So, it's not a replacement for some particular C++ feature per se, it's not a feature in the sense you mean at all, it's just that

borrowck is a semantic check. So, it's not a replacement for some particular C++ feature per se, it's not a feature in the sense you mean at all, it's just that while C++ and Rust both have these same semantic rules in place, Rust checks them and C++ does not. When you as a programmer inevitably get something wrong and break the rules, in Rust your program won't compile, in C++ it just has some arbitrary misbehaviour, maybe you notice, maybe you don't, maybe it matters, maybe it seems benign... until 8:26 tomorrow morning when suddenly it blows up and makes your customer very angry. In C++ the result of breaking semantic rules (not just those checked by the borrowck, most of the semantic rules in the language) is IFNDR - your program is Ill Formed, No Diagnostic Required - your entire program has no particular meaning, there is no explanation for what it does, shrug. In Rust it doesn't compile. For people whose overriding mission is to get the code to compile, C++ is very attractive. Broken garbage? Meaningless nonsense? Not my problem it compiled so I went home. If you want to write software that works, that seems like you didn't do the hard part.