The Lava Waders are absurdly rare and don't give you nearly a good enough reward for their rarity. You only need lava resistance maybe twice in a playthrough MAX and even then the job is done better by potions, which last much longer and let you completely ignore EVERY effect of these boots (obsidian skin potions work on fire blocks too). I have a few proposed solutions to this, which could either be added together or just one.
- The Magma Charm and Lava Waders now give complete immunity to lava, which sounds overpowered until you realize that that liquid only appears a little above through the bottom quarter of the world, which has literally no exclusive loot after the Wall of Flesh. (except for the unholy trident, which is a weak weapon anyway, and the Fire Feather, which is literally Just an Ice Feather that isn't available as early.) Also make the obsidian rose have lava treated as honey.
- Make three guaranteed water chests spawn in each ocean, with a moderately uncommon chance for more to spawn there too. Water Walking boots are far too rare for how useful they are right now. Also raise the Magma Charm's chance to 10%, because again, it's way too rare for how underwhelming it is.
- As a more bizarre alternative, make all three of the components unobtainable, and just have lava waders show up in any cavern chest with a 10% chance. This would make them actually worth all the effort you put into getting them.