Sure if you restrict yourself to a subset of c++ that avoids the more unsafe features, you can avoid some of those problems, but not all of them. And IME, a lot of c++ in the wild still uses those unsafe features, especially when interfacing with c libraries. And even if you always use smart pointers and make sure you always initialize your variables there are still plenty of ways you can get undefined behavior in c++.

> This reminds me of how all the people carried on as if they were making the kernel so much safer not realizing they needed to use unsafe rust.

Those are not contradictory. Confining unsafe code to a few unsafe blocks makes it easier to identify areas that need closer scrutiny. Just because there are unsafe blocks doesn't mean that using rust in the kernel isn't making it safer.