Make mountains as pegs

Mountains should be either dense (No caves) as if mountains have pegs. or have very large caverns. Right now there is not enough space between sea level and bedrock so mountains can have large caverns and really cool cave gen with a lot of space. or just be dense. This way it wont ruin game play since there will be a chance that mountain you found has a cave.

Main Point:
Either mountains are dense (No caves) or mountain have large caves (more space for caves).