In the USSR, you usually don't have a spare guest room. An unmarried young man would be lucky to live in a separate apartment; otherwise, it is usually just a bed in a dormitory. At best, it is a one-room (12-20 m2) apartment with a kitchen (10 m2). A hotel is too expensive, so you put your guests into your bed, a folding chair, or a folding cot and go to the kitchen to sleep on a mattress. There were families of 4-5 people who lived in such apartments permanently.
Even in the US, I don't know many friends with enough living space to have an entire spare guest room.
When friends visit, they sleep on the living room couch or an air mattress. Is this not typical?
Flippant answer: in the U.S., in your twenties, you have no spare space, and visiting friends sleep on your couch. In your forties, you have a guest bedroom, and visiting friends stay at a hotel.
Possibly more accurate answer: it depends on what kind of housing people live in, if they have kids, and if they work at home. Most residential houses were built for couples with children, so if someone owns a house and is single and/or childless, they likely have spare bedrooms that serve as a home offices, hobby spaces, or guest bedrooms. People living in apartments usually don't pay for more space than required for their daily needs.
To be fair it says "In a nearby apartment packed with guests" - if your house is oversubscribed, the host gets the worst accommodations is pretty common worldwide - "He had a horrible thought that the cakes might run short, and then he—as the host: he knew his duty and stuck to it however painful—he might have to go without."
That's some Soviet shit.
Possibly more accurate answer: it depends on what kind of housing people live in, if they have kids, and if they work at home. Most residential houses were built for couples with children, so if someone owns a house and is single and/or childless, they likely have spare bedrooms that serve as a home offices, hobby spaces, or guest bedrooms. People living in apartments usually don't pay for more space than required for their daily needs.
It doesn't seem that crazy that there would be very little space. Parents and/or grandparents probably got the bedroom, some friends the living room.
I routinely tell her "I want our daughter to have everything you didn't get as a kid".