I've never seen a home brew adventure or campaign world that wasn't garbage. YMMV, of course but my anus reflexively clenches when any DM describes their campaign.
Usually cause they are really not that special or creative but everyone thinks of themselves as JRR Tolkien.
Knew a girl that came up with a setting (in her case it was for a Larp-group) that must have been the most one of the most ridiculous and poorly thought out settings in the history of worldbuilding.
The first thing that struck me was that it mentioned the island was populated by 70+ Million people, which is an instant giveaway that the creator wants to emphasize how "big and powerful" the setting (and thus their characters) is, sort of like a dick-measuring contest for idiots. "My imaginary nation is more powerful than yours, since it has much more imaginary people! Therefore, I am more important than you!" It's usually just an excuse to pull off ridiculous amounts of so-called "telling" and to give their characters a thin veneer of status and influence.
And if you think that's stupid check out the rest:
The "island" was so large, compared to our Earth, it would reach from Stockholm to South Africa and from New York almost all the way to Japan, while covering all of Eurasia. And this was supposed to be only one of several islands. There was supposedly another, larger island to the north.
Considering the number of inhabitants, this would mean that Alaska (ice and sea area included) would have at least ten times the number of people per square mile compared to this super-continent-sized wasteland. Traveltime by land would be measured in months, even between small hamlets; years, if you wanted to travel from one capital to the next.
And that's before we even get into lore.
There were like 7 nations with wildly different techlevels (reaching from early middle ages, where mail armor was state of the art) up to a place with steam engines (that based on its general techlevel should have been fielding early machine guns and repeating rifles). Every nation had its specialty that no other nation would be allowed to copy. According to the lore, this system was recently started after a prolonged, bloody, several centuries long war, which was concluded by dividing responsibilities and this supposedly helped consolidate peace. That means there would be one nation that would train soldiers, one nation would train healers, one nation would train hunters, one nation would train merchants and so on. I think there was one nation that trained librarians for some reason. And if Nation A needed an army, they would be forced to buy it from Nation B. How this is supposed to work is anyone's guess. Just the idea of going "Yup, and no one is allowed to train soldiers except our nation" and everyone going along with it right after several generations of war is making my head spin.
Mind you, all this for a group of 5 players that wouldn't even play in this setting, since they were essentially exiled.