The demarcation point between those two is called "The Hickman Revolution" by some scholars; when dungeons and the adventures around them became less about "a bundle of mechanics containing loot" and became "a showcase of interactive cultural tropes used with game mechanics to tell a story."
It's very much analogous to the transition of video games from arcade oriented "high score" games like pac-man and space invaders to more narrative oriented home games like Adventure or Mystery House
1e characterizes better as each individual DM homebrewing a unique world setting, whose only limit is imagination. It starts locally and expands outwardly: points of light punctuating swaths of a dangerous darkness. Choosing adventure locations likewise encourages the DM to decide where they are and what is around them, thus populating a world map, one point of light at a time. 1e assumes DMs and players want to tell their own stories.
2e-3e is corporations publishing a world setting, with many purchasers sharing the same world setting. Here the idea is of an "official" setting, where consumers accumulate stray details mentioned in passing in the official products for the setting. Fans network to extrapolate from there, to fill in all of the darkness. A fascinating aspect of 2e is, errors and mismatched texts and images, provoke explanations that then generate enormous amounts of "new" information.
5e 2024 can do either, individual unique or corporate shared. The core books are setting agnostic (except for assuming a vaguely medievalesque magical realm). So the spirit of 1e is alive and well. DMs really can use the core books to easily homebrew unique worlds. At the same time, there are corporate settings, like Forgotten Realms and Eberron, plus indy settings, whose DMs can purchase, share, and flesh out via fan sites. The official settings are remarkably diverse, from Theros, Ravnica, Dragonlance. Soon, there even seems to be a return of Dark Sun, plus a scifi Exodus setting with a thoughtful premise speculating about near-light travel. The diversity demonstrates how versatile the 5e game engine is.
2024 also has settings in between, such as the opt-in Flanaess map in the Dungeon Masters Guide, with only broad strokes for descriptions, that the DM is to detail. The Dales regional setting seems to lean into this style. The area is mostly swathes of dangerous darkness, spangled by certain notable locations.