P.S.: We get these "why are diamonds rare" threads every time a new modpack comes out - just try the forum search. And every time someone goes and scans a statistically useful area with an external tool and gets exactly the expected average amount of diamonds per chunk. There is no actual shortage, people just think there is because of:
- Clustering Illusion: diamond distribution is fairly random, and it's perfectly possible to have a bad luck streak, but people misinterpretate it
- Increased Consumption: because each new mod adds additional needs for diamonds, people have a harder time satisfying the demand, and therefore it feels like diamond is harder to come by when in fact they still find the same amount as always
- Richie Rich Syndrome: Coming out of a well established world where quarries and turtles and tunnel bores funnel a neverending stream of diamonds into the storage chests without the player having to lift a finger, it feels twice as difficult when coming into a new world where they have to dig out every diamond by hand.