it depends in how much chicken you eat in proportion to veg.
If you have been brought up with parents who were brought up in ww2, thier view of a portion of veg is probably considerably smaller than those who were not subject to rationing.
If you were brought up with not much money, then portions of meat were also small.
if you are budgetting with not shopping, also portions will be smaller.
If you are cutting back on meat as part of protecting the environment, then you will also use smaller portions.
if you eat a veg rich diet then the meat is not the main part of the meal. when cooking things like chicken curry or pie, the size of the portion is smaller.
regularly managed to make a chicken last a week for two toddlers and two adults because a roast meal was full of lots of different veg, stuffing, yorkshire puds etc.
however, If I were left alone with a freshly roast chicken... and had none of the concerns listed above well, there might not be much left!