Does Rust really solve problems that modern C++ using the STL doesn’t?

Im genuinely asking as someone who is open minded and willing to learn Rust if I can see the necessity.

The problem I’ve had so far is that everyone I’ve seen comparing C++ with Rust is using ancient C-style code:

• Raw arrays
• Raw pointers
• C-style strings

And while all those things have tons of problems, modern C++ and the STL have solutions:

• std::array/std::vector
• smart pointers
• std::string

So id like someone maybe a little smarter than me to explain… do i actually need Rust? Is it safer than modern C++ using the STL?