This isn't even uncommon. I've stayed in a lot of converted hotels or SROs (single room occupancy, basically bum hotels) that would make this place look nice.

Honestly this reminds me of the Alexandria in downtown LA a lot. The Alexandria used to be an upscale hotel when it opened, Mae west, buster Keaton, and Frank sinatra were all regulars there (one of the guys I moved things for found a bunch of old brass name plates in a storage room) but since then it slowly crumbled into ruin. At the time I moved in it had transformed into a small insular city, there were different rooms where you could buy anything without leaving the building (many tenants were professional shoplifters or "boosters") especially drugs. It was commonplace for people to make the rounds door to door looking for drugs, to the point that when I heard them is put a sign out our yell to save them the trouble. I should mention that the Alexandria is thirteen floors high counting the penthouse. Speaking of the architecture, there was a huge dilapidated ballroom on the second floor with a single out of tune piano that people would randomly play, and a bunch of different shops scattered between the first two floors (a bar, a grocery, a resteraunt on the first floor, a ballet company on the second and an acting theatre on the third or fourth) Which was a bizarre juxtaposition to the world inside. Also, there were all manner of "secret" passageways and hidden rooms, to the point that to this day of I was trying to run from someone I would go through the Hellexandria. Then there were three people on the twelfth floor, most/all of whom had lived there since forever and never left their apts. One of my business partners introduced me to one once, and her place was a Victorian fever dream, all lace and gilded wood and French opulence, covered in dust and packed together. It was very surreal. The building itself wasn't dissimilar, all the metal was brass, much of it intricate and beautiful, all of it tarnished, dented or broke. The delicate tilework was missing in large swatches in many places, where on our two had broken and junkies had started prying up the rest. There were cul-de-sacs near the elevators where people dropped off their garbage next to beautiful views of downtown, and every day, all day, there was a woman who screamed in a foreign language out her window from the time she woke up till the time she passed out. I have so many stories from that place (not to mention some of the other hotels I've lived at), but I've already gone on too long. So while this place might seem eerie to some, it's just life to others.