Hard to justify for a beginner? Sure.
"Can't tell the difference?" is not true, once you're dealing with small enough parts.
Can I use a magnifier to solder 0.4mm pitch parts? Sure. Would I prefer a binocular microscope? 100%, every time. Both usable, not the same.
> "Can't tell the difference?" is not true, once you're dealing with small enough parts.
Yeah, but that's the qualifier - "small enough parts". Go small enough and even an expensive iron isn't going to help you.