People who can trivially afford it are still apparently insufficiently justified because not everyone can, as are people who would not consider a cheaper substitute suitable because other people would be fine with the substitute.
No I never said that, and if you look at the deltas I've awarded so far in this post, they've both been about money.
However, if imperfect substitute goods will suffice because some consider them to, that becomes entirely arbitrary. You may consider the brisket to be insufficiently substituted for by a different piece of meat one can prepare at home, but others would consider it an acceptable substitute (which may likewise be "good in different ways" or "have their own sentimental or subjective value").
But this is what I was referencing in my initial post to compare it to foods that are labor and time intensive like smoked brisket, require specialized ingredients like eel sushi that may be hard to come by, or are technically difficult like Korean style double fried barbecue wings. For foods that are difficult to prepare, complementary eating habits are much more acceptable as there is added cost of more time, labor, effort, and the price of potentially expensive cooking ingredients or equipment. Making burgers instead of brisket for example, or buying brisket from a restaurant is a very different kind of substitution compared to avocado toast that is not time intensive, labor intensive, technically difficult, or comes from hard to find ingredients. In its most basic form, it's a shade above peanut butter and jelly in terms of difficulty to prepare.
What I was looking from this is not an explanation that for some people, it's worth the cost because of subjective taste and their monetary situation. I understand that, I never said anything about them being an objectively bad decision, everything I have written is subjective. What I am looking for is a more detailed explanation of why someone might choose to spend as much as $20 in their own personal life, on avocado toast, and whether that was/is something they do regularly. Because I've had avocado toast in restaurants and to me the slight better quality for a low-quantity, easy to prepare food is not personally something that I feel justified in spending my money on.