NBREECH

If you find the perfect cave (a large noise cave with the floor just above lava level and the ceiling at -30 or so, you can find diamond veins quite easily, but in practice you only get about as much diamonds as a good cave from before the update since the veins are much smaller (usually 1-2 ores, sometimes 3 or 4).

I completely agree that the amount of diamonds in noise caves is generally balanced, it's that the old caves and shafting, the primary established way of mining for ores for the past decade, have become many times less effective. (I've broken entire unbreaking III netherite pickaxes with finding only 1 or 2 tiny veins that barely make up for the pickaxe I wasted let alone the immense amount of time spent shafting). Additionally, a world can only have so many large caves in a given area. Players should be able to shaft and explore tight cave networks to find ores like diamond without having to march 3000 blocks to find a new cave. I imagine this problem would be worse on multiplayer servers.

@BurnedCoal I'm not so sure - the balance is so messed up its hard to figure that all the side effects of the last change are intentional, and I know the devs are on record saying they wanted shafting and caving to be about equal. It's right on the line between bug and intentional feature - that's why I also made a post on the feedback website about this.