With the recent update collecting bone blocks has become very easy. Even though the soul sand valley is a scary place ghasts and skeletons can be easily avoided with proper precautions while you collect bone blocks.
The bone burrower will change this it will have a random chance to spawn upon breaking a bone block and the bone block will still drop. It is larger, slower, and stronger than its overworld cousins the silverfish.
The bone borrowers heavily bone plated head protects it from incoming damage to it's front side, and It's immune to lava damage. And It will break through most blocks to hunt you down
except for of course the toughest of block like obsidian netherite blocks ancient debris etc... upon death the bone borrower rarely drops it's bone plate which obtaining 4 can be used to craft boots. The boots will protect you from magma block damage and lava damage so long as your less than halfway submerged.