I use them when they're easy to type. For me, that's on Android, macOS, and anywhere I've configured a compose key.

Angled quotes I use only on systems on which I've configured a compose key, or Android when I'm typing Chinese.

I don't like any kind of auto-replacement with physical keyboards, so I turn off "smart quotes" on macOS.

Anyway I use characters like that all the time, but it's never auto-replace.