The average Joe who has no skills wouldn't survive.
The average joe who has no skills in carpentry can survive without carpentry.
Technically speaking having dozens or hundreds of people in a single location... trades would eventually pop up.
Yes only relevant trades with immediate benefits
And the environment we see is incredibly unrealistic.
It is realistic in the setting it takes place in, there isn't just humans to worry about.
How many centuries before someone picks up a Pre-War book
You're assuming the majority of the population care to read Pre-War books when it's fact only those who aren't already struggling to survive have the time for it.
on how to properly work wood/steel or even mimic the most basic functions of a house? They have plenty of solid examples to work from considering there is plenty of Pre-War houses still standing.
That's literally what they've done...now because it's not a 5 star mansion is another matter.
Megaton has the ability to make steel houses, work metal and have piping. Yet plugging holes is impossible? Get real man.
Megaton also uses their scrap to maintain their piping and pays the Wanderer for more scrap, don't be a jackass because you zone out the entirety of Fallout 3
The average Joe built this world. Not super geniuses or anything. FNV had plenty of examples of houses that didn't look like rubbish while still feeling apocalyptic. Goodsprings for example.
The average world built this world during periods of peace and more abundant resources than Fallout. Why are you guys so dense to understand a society can't recover as quick when there isn't the knowledge, resources and respite?
Every example of "Oh well X can do this they have 200 years!" Whilst ignoring the survivors of the Fallout setting don't have the luxuries to rebuild in a timely manner.
Goodsprings is able to rebuild a semblance of a town (Even though it still looks like shit) because
A) Their territory isn't irradiated hell hole thanks to Mister House conveniently shooting down the nukes
B) They're in a peaceful area of the Mojave where the greatest threat they faced were a handful of convicts.
C) They actually have exceptionally (For a small town) well trained people that lived there.
None of that is applicable to the East Coast and that's why their shit is all rushed up.