It would depend on fire codes, but every room I’ve ever seen in the US does have sprinklers. Often, the lower-rent rooms are older hotels that had to retrofit the sprinklers in, and this often means more of the sprinkler head and/or pipes are visible (to limit the amount of sheet rock that has to be cut away and replaced).
When I managed apartments, I saw records from a previous manager about a sprinkler pipe that burst. (No word on why). It flooded six apartments - the one with the break, the one next to it, and of the ones below those two. The cleanup was a horrendous mess and the tenants lost a lot of furniture and other items to water damage and mildew.
About 10 or so heads per year for the past 15 years - yeah, I’ve seen them in operation. I’ve been under them with a pair of wedges to close heads caused by mechanical damage (forklifts and contractors), frozen pipes, and one Grinnell on/off head that didn’t get replaced in the 70’s with the rest of the world. I’ve also been underneath them fighting (or trying to find) an actual fire 20 or 30 times. Yeah, I’ve seen heads go off - up close and personal.
Pipe size does not determine the rate of flow of a sprinkler head. The size of the head determines flow rates - it’s called the K factor. Put it in the formula Q = K * sqrt P where Q is the flow, K is the K factor listed for that head, and P is the pressure at the head. Almost every head you see in an office, hotel, apartment, strip mall, or school is a half inch head with a K factor of 5.4 to 5.6. If you have a K=5.6 head, at 80psi residual, yes, you will get 50 gpm. The system is not designed to flow that much water - 50 gpm is overkill. A “properly designed” system will flow maybe 35 gpm from a normal head.
As for comparing a high rise to a box store, there is no comparison that can reasonably be made. The correct heads in a Wal-Mart are called ELO - Extra Large Orifice heads. They have a K factor of 12 to 18. That’s 84 to 126 gpm at 50psi. That is a huge amount of water. Huge water means huge pipes. Huge pipes means huge expense - not something you would need or see in a high rise, there isn’t enough stuff there to generate the fire loads that an ELO head would be used for. High rises are office buildings, not warehouses. Look closely at the heads in a high rise - they’re half inch, K=5.4 to K=5.6 heads, the same you’d see in any office.
To make a flood look like a lot of water does not take much. Dump a gallon of water on the floor, it looks huge. Sprinkler systems do a lot of work with a comparative little bit of water. The smallest hose line I’m going to drag in flows at least 125 gallons per minute. If it’s a high rise, I’m looking for 250+. That’s the true value of sprinklers - they knock the fire down at the beginning with a little water before I have to wreck the place with my very inefficient water application devices and techniques.
My friend smacked a sprinkler head in her bedroom when she was shaking/airing out her sheets. It set off all the heads in her condo unit and the fire alarm activated for her whole building. Luckily her neighbor was a fireman who knew where the shut off valve was. Still, the flooding caused quite a bit of damage to walls, carpets, furniture, books, wall hangings, etc.
My sister-in-law works at a Holiday Inn here in Ontario. Within the last couple of months a bride hung her dress on the sprinkler and set it off. Apparently there was 4" of water before it was turned off, damaging 4 rooms on 2 floors and the bill is already over $90,000.
The hotel staff were not allowed to turn off the water until the fire department responded. Doing so would have resulted in fines. Obviously the cost would have been less to take the fine, but the safety of the guests takes precedence.
