The phrase "You should be grateful, some people are worse off" is one of those comments that makes your skin crawl. The person who says it isn't trying to help, comfort, or give any useful advice. No, they're just trying to put you down, minimize what you're going through, using the excuse that someone else has it worse. The reality is that the person saying this is just satisfied knowing someone else is suffering because somehow, they feel better knowing they're not the only one unhappy.
This phrase isn't about empathy; it's a sneaky way to make you feel guilty for your pain, as if it's not serious enough to deserve attention. The person saying it doesn't want you to get better, they just want you to stop complaining and feel bad for even feeling upset. In their head, the pain of others is just a way to tell you to shut up and stop feeling so bad, because, after all, someone has it worse.
But the truth is, the person who uses this phrase has no intention of listening to you, understanding you, or helping you. They're just trying to put themselves above you, probably to feel luckier or "stronger" than the situation. Their happiness depends on someone else suffering more than them. It's a petty mentality that feeds off seeing others down to feel better, as if suffering is some sort of competition where you need to prove you're doing better than others.
If they really wanted to be supportive, all it would take is a "I understand" or just listening without making comparisons. But no, with this phrase, they just want to make it seem like your pain doesn't count. It's a phrase that should be completely eliminated, because every time it's said, it only undermines your experience and perpetuates a way of thinking that is anything but empathetic.