In my own experience with this both from working in a shop as well as having bikes (direct) shipped to me.
The bike typically comes in the box with the back wheel on, the cranks installed, brakes installed, der. installed. The handlebar is often turned sideways packed along the top bar with the cables all run. The stem, seat, reflectors, front wheel, pedals will generally be packed in the box, not installed.
At the shop we would ALWAYS take the headset/BB/wheels and check to be sure they had grease in them. You would be surprised, even by the bigger brands how often there isn't any. We always checked the tightening of the "hub" (gears on back, name escapes me). After putting the bike together in its whole form, check and set the brakes, check and set the der., pump tires and take it on a short ride through the parking lot to be sure it is shifting and stopping correctly. In most cases this took about 20-30 mins tops.
The added value for the customer in this was that the shop typically offered some level of "aftercare" in regard to that first der. tune and brake tune it will need after some cable stretch (when applicable), as well as truing the wheels one time. VERY BASIC fit was offered, but if they actually wanted the 'custom fit' level, that was an upcharge. Most of the time we would also add accy. if purchased through us for free. So, put on a rack, computer, lights, fenders and so forth. During this same period, if the cust. wanted better bar tape or a better seat, etc. that would just be part of the buildup.