Lava, cacti, fire and explosions shouldn't erase certain types of blocks.

Ever since the old days of Minecraft there have been lava, cactus and fire blocks as well as explosions. They have the simple but monumental game mechanic of hurting players, mobs and entities and deleting items. This at the time made sense and served as a challenge to avoid getting your precious belongings from getting destroyed as well as having a way to destroy unwanted items. However nowadays with the new updates coming out the game changed and improved greatly versus how it was in the beginning. But now in contrast to the rest of the game these mechanics have become antiquated and flawed. I expected there to be many posts about this but I barely found any if at all.

The literal container that holds lava gets deleted in lava. Only cheap renewable items should be deleted by cacti and fire like food, plants and seeds, dirt types, wood types, sand types, gravel etc. And lava should burn a wider range of items like stone types etc. But obsidian, armour, buckets of any kind and all types of ores and ingots (except for coal) should not burn in lava or at least float to the surface and burn slowly. Especially for emeralds and diamonds. And items caught in explosions most notably blast resistant blocks should also behave as they would when not in item form.