You mean it can remove a memset() that doesn't cause the observable behaviour to change?

For the sake of argument, can you show me some example code where it would be conforming to remove a memset() call? Preferably a realistic example and not a Google'd copypasta. Because it's all too easy to just regurgitate things you heard and think you understood, but no so easy to demonstrate it yourself.

I agree that it would be rare for a memset() used for initialization to be removed, but this is a good recent paper that gives lots of examples of when stores are eliminated in practice:

Dead Store Elimination (Still) Considered Harmful

https://cseweb.ucsd.edu/~klevchen/yjoll-usesec17.pdf