Ideas like these make cool mods, but poor vanilla mechanics, because, as has been said, they're inconvenient. One bar to micromanage is okay, and the hunger bar does have a purpose, and food items are ubiquitous enough that keeping it topped up isn't much of a chore. Constantly finding plants to stamp down random debuffs or hunting for glass to store water aren't everyone's cup of tea, and would, in fact, be invasive and annoying, forcing the player to potentially carry unstackable items or craft elaborate recipes just so they don't die in a cave somewhere because they didn't eat enough.
Some people would enjoy this challenge, but others would find it to detract from the simpler aspects of the game. Making it a gamemode is avoiding the issue; it wouldn't fit with the others.
Perhaps, if you added a little more detail, you could post this in the Mod Suggestions forum? It wouldn't fit much with the original game, but I would definitely install it as a mod.