Only if you're lucky enough to live in one of the few well-maintained ones. At least in Russia, many are falling apart with loose handrails, water damage, sketchy elevators and mold.
There was an architect, Le Corbusier. He was a socialist, so his projects of future cities involved a lot of public spaces where people spend their free and working time, while a person's home was just a small area for sleeping and eating breakfast. The Soviets took the idea of small personal homes, and dropped the "nice public areas" part.
It's cold in the winter because the walls are quite thin
You can hear your neighbours loudly speaking
I was lucky to have a normal-sized room in a later "Brezhnevka" house, but many of my classmates had rooms (if they had a separate room at all) where you had a bed, a cupboard+desk combo, and a chair in the middle, that you have to remove to get to the window. Japan-sized stuff.
Speaking of Le Corbusier, as his main (I know, that's subjective) achievement was a technical approach to ergonomics - all sizes in his projects were based on human sizes and proportions. Meaning that a height of a ceiling is a height of an average adult man raising his hands, + some space. It worked, and it's cost-effective, but you really like some extra space, and have more than 3 sq.m. toilet.
They're livable, but can also be really bad depending on the maintenance of the building and the previous tenants. The problem is the terrible design of some panelák style dorms- see Strahov, which is a dystopia for many reasons.
I recently moved to a German city that, whenever I mention it, is described as "ooh it's such a beautiful city!" because it wasn't bombed to shreds in the war and a lot of buildings are from 1900ish and older.
Honestly I would rather prefer to live in a building like the post. The apartments often are cut more efficiently and fit better for a family. Yeah, the outside isn't as appealing as around here but I don't live on the outside of my house, I live inside of it, so I barely care about its outsides. The other side effect of eastern blocks is that the density per square km is amazingly high. This also leads to supermarkets etc being everywhere. (I am, of course, making generalizations here.)
Of course I need to say that the energy efficiency in old eastern block houses is also awful.
But I don't want to bash the 1900s houses too much. At least they have 4-5 levels. That's still better than single family homes in the middle of a city (talking about you, pipe smoking guy in the middle of Sendling).
We live in a house from 1900 and thanks to a lot of work our apartment has the energy efficiency grade A to B. We will also get a heat pump in the next few years. We have PV on the roof (I'm not sure what for right now), our windows are triple glassed and we have two heat exchangers thingy that sucks air from the outside and pushes inside air out. A couple of months ago they also insulated the roof of the basement better.
We are very lucky that the owner is behind all these works. Most aren't, but it is to show that you're absolutely right and how much can be done and improved. (However, I still don't like the cut of the apartment or not having an elevator/barrier free access to the basement. And the bugs.)
The best fucking joke is that those buildings and neighborhoods despite being absolute piss poor quality are waaay nicer, roomier and greener than what capitalist development corpos build these days. So yeah, free market for the win i guess.
Edit: I've looked up the picture and confirmed these buildings are some of the empty city that China has constructed. I'm not sure what all the downvotes are for...
These buildings have appeared in countless different places. I guess no one's seeing any humor in it....
Edit to add that I'd genuinely like to know where you saw them and inquire if you know any background on them. I'm very interested in the origins of these projects. I feel like I'm in one of the best places to learn from people with first-hand knowledge.