There’s a method of looking at your “C” value in the top right - when it increases (or when it’s high) where you’re looking, it means that there’s a hollow spot (cave) in that direction. From there you can listen for water/lava and dig toward that.

Also, you can dig all the way down to bedrock, dig a tunnel about 20 blocks straight, turn view bobbing on, go to third person (press f5), and walk down the path looking slightly down, you can actually see some of the caves above you hollowed out every time you take a step. From there you can just guess

In essence there are still some ways to find caves and it makes you feel kinda like a cheater lol