1. I already know the most about the thing and have already found the one that either maximizes the utility/price relationship or maximizes utility below my price sensitivity threshold.
2. I don't know the most about the thing yet and have therefore not decided what I want.
The problem with the first is obvious: I either already own the thing or am about to, so the gift becomes just a cash transfer, and I don't need or want cash transfers from my friends.
The problem with the second is less obvious until you know that I dislike owning things and only choose to own things when they meet the first category.
So what's the answer for people with enough money and interest to buy good things for themselves?
Don't buy them utility gifts if you aren't more passionate than they are.
Buy them only weird sentimental things and quirky consumables that don't have to meet a personalized utility threshold. A small piece of artwork that comes with a note saying "This made me think of you" carries sentimental value and will make the receiver think of giver every time they look at it. A weird chocolate with ants inside will be weird and fun and it won't matter if it isn't the best weird chocolate with ants inside.