Yes, because you remove a whole class of errors that might be exploited. Might be hard, might even be impossible, but they are there waiting to be taken advantage of.
Interestingly enough, very high performance java is a bit like rust. Almost all memory safe, except a few (10-100) lines off crazy unsafe stuff.
Of course it is possible that your C code has no memory issues and is verified to be safe, but I would not bet any money on it.
Also at the moment custom code is the last entry point for a hacker, but once all other things are hardend its the last guaranteed leak in the ship.
I also understand where C semantics can lead to faster code than e.g. java today. But I suspect that edge to disappear within the next 3 years. Just like java is going to make heterogeneous compute easy its also going to improve streaming over memory for speed where needed.
In an earlier comment you used as an example of an unforced error "we wrote our custom database engine that only ever runs serverside in C".
Are you saying (with this comment) that for such use cases, developers should use Java/Python/Go/Lua (vs C/C++)?