I think the big difference here is that it's opt-in, off by default, and also not included with shared images by default. This is a feature because you use it

I think the big difference here is that it's opt-in, off by default, and also not included with shared images by default. This is a feature because you use it when you WANT to be able to demonstrate an image wasn't altered / was yours, like for a journalist. This is an actual question, not a dig: what do you mean by non-removable?