This was first the case in 1.7 (not a typo), but is even worse in the Caves and Cliffs development datapack.*
Ever since the world generation was changed in 1.7, caves were significantly nerfed. This makes dungeons also significantly nerfed.
An example of this is the fact that I have played Minecraft for hours on end and found exactly 1 double dungeon ever (where a dungeon generates on top of another), and that being with the help of an outside source (Chunkbase), and I had to play in 1.16.5 (Actually, I checked later on and it wasn't technically a double dungeon, just two dungeons that generated about 30 blocks away from each other, so that doesn't even count). However, upon loading a new world in 1.0.0, I search around for about 5 minutes and find a double dungeon (recall this is before spectator mode). This is evidence that dungeons were much more common in the past, a staple of caving. Now they are incredibly rare (in 1.7-1.16.5 they are about 2.5x rarer than in 1.6 and before).
In addition in 1.7, they changed the y-coordinates that dungeons can generate from 0-127 to 0-255, which since caves rarely generate above 127, majorly reduced dungeon generation unintentionally, making them in a default world about half as common. In the Caves and Cliffs development datapack, they are even rarer, being that it searches from -64 to either 255 or the build limit, I'm not entirely sure.
(2.5x rarer comes from a number I read that said caves are about 23% rarer and the limit that dungeons can generate has been doubled. 23% ~= 1-.80, .80^-1 = 5/4 = 1.25, 1.25 * 2 = 2.5)
*I've done some more research, and it is possible that dungeons started to get rarer even before 1.7. Nonetheless, I was able to quickly find a double dungeon in 1.6 (not a typo).
Linked issues
is duplicated by 1
Attachments
Comments 7
I prefer forward-resolving MC-215073 to this more detailed ticket.
The first and second half are two very similar issues with very different causes and the same fix: to increase dungeon generation by a large amount. The former was first an issue in 2013, and the latter is a new issue. The latter is also probably is a duplicate but being that it isn't fixed despite being resolved, might as well just be forward resolved to this issue. Or this can be marked as clones it.
Can confirm in 1.17.1. I did some analysis using the seed 225030 near the spawn chunks, from (-28 -5) to (-4 19), using NBTExplorer to find dungeon chests and mineways to visualize the map. I have attached an edited map of both versions with X marked on the chunk that contains a dungeon (may be off-by-one in some cases, because dungeons can actually span two chunks).
The distribution in 1.6.2 seems a lot more spaced out and regular than in 1.17.1. There were 10 dungeons in the area in 1.6.2, and 7 dungeons in 1.17.1, but there could be one or two dungeons that I might have missed in both versions. If someone could double check the results, it would be much appreciated.
Could potentially be a duplicate of MC-215073 which was fixed in 21w15a.