Forgive me if I'm a bit down on these methods. I've never come across a use case where they are definitely the way to go. There was a time when <object> was the only way to use SVG, but those days are over.
One of the reasons to have done it this way in the past (rather than use <img>) was that the SVG retained interactivity, like hovers and animations. Browsers are starting to make that work with SVG-as-img though, as I write this.