I found c ABI a bit too difficult in rust compared to c or zig. Mainly because of destructors. I am guessing c++ would be difficult in a similar way.

Also unsafe rust has always on strict-aliasing, which makes writing code difficult unless you do it in certain ways.

Having glue libraries like pyo3 makes it good in rust. But that introduces bloat and other issues. This has been the biggest issue I had with rust, it is too hard to write something so you use a dependency. And before you know it, you are bloating out of control