Well it is not just Avocado toast. Many spend frivolously on a daily basis. Sure you can afford it, but just think how much those 3-4 meals a day are costing you. As someone said, a loaf of bread is as little as .79 cents, add in some meat and cheese from a deli and you have 10 dollars of food for a week, instead of 10-30 a day on whatever you think of buying.
Last night I bought toilet paper from a gas station because I did not want to drive an extra mile to get it from the Grocery store. Cost me 4.99 for four small rolls, doubt they were even two ply.