It's wrong because it's simply irrelevant. Would it change anything about your situation if you did have it worse than everyone else (other than not getting comments like this)? I presume not. You're still suffering, full stop, and that's something that should be alleviated.

There will always be someone who has it worse. So the war casualties in Iran allegedly have it worse. First off, do they really? Some might argue that prolonged suffering is worse than a sudden death via a missile. But even without that opinion, there are people who have it worse than the Iran war casualties. You could be stuck in North Korea sentenced to a lifetime of hard labor and have terrible back pain making every hour of that hard labor torture. Does that mean the casualties of the war in Iran aren't relevant anymore? I'm pretty sure just about everyone would answer no.