How is it too manual compared to eg C# where I need to implement IDisposable and wrap use of variables in "using" to really ensure something is cleaned up when

How is it too manual compared to eg C# where I need to implement IDisposable and wrap use of variables in "using" to really ensure something is cleaned up when I want it cleaned up (without risky memory ballooning relying on the GC)? C++ destructors to clean up your resources are really neat. And deterministic - you know when stuff is going to get cleaned up. Or was it some other "manual" feature that's too much of a burden? Honestly curious.