[dathinab]

The scary thing is:

Handling uninitialized memory is hard in C++ (and C), too.

You just don't notice and accidentally do it slightly wrong (mainly in C++, in C it's harder to mess up).

[queuebert]

Exactly this. And also avoiding initializing memory with zeroes or something is often premature optimization. Very few programs are performant enough to notice the difference.

[dathinab]

In my experience the most common use case for zero-memset is not optimizations but to reduce fallout if you happen to initialize a field..., like a newly added field.