>For example, 1 tablespoon of oil is 120 calories and 14g of fat.

You should not use them, but for some foods they may work. So if you have a person who isn't going to track the traditional way, then tracking something is better than tracking nothing.

Let's say you are consistently undercounting calories. In that case, free app like MacroCodex (which uses adaptive TDEE tracking) can offset that error and estimate your maintenance calories helping you make better adjustments going forward.

Deficit = TDEE - Intake

macrocodex will simply lower your tdee estimate if you are undercounting, then you'll cut calories further and you'll end up in deficit and lose weight.