Well, you need to have a "perfectly'' compatible group. Even the food thing is horrible. Sure the standard is wasting huge amounts of time "deciding what they want" or other wise being annoying about getting food. For many people this is a way of life that they do everyday.The whole it takes a perfect group to have any sort of collaborative play experience work take is just not true. What it takes is just a group of broadly compatible people who are willing to sometimes have tough conversations, but like not like much tougher than deciding between burgers or Chinese food.
My typical weekend game is 5 hours with a food break in the middle. Now, I wish to spend that time playing the game...NOT watching some slow idiot try to decide what type of food they might kinda want to order in the next half hour. You take more then five minutes to think about food, you will ejected from the game. I do not waste game time, and only want players that agree with this way of gaming. Once the food is ready, we break for 30 minutes to eat: if your a slow casual eater that likes to waste all night eating...you will be ejected from the game.
It's not "fragile".... Like I said, as long as the DM and players all agree it all goes smooth. The player character has 10 hp, and takes 12 damage. The player looks at the DM and they say "oh, make that damage 9". Then the player and DM high five and the game goes on.....There are plenty of reasons why a more callaborative approach to setting design might not work for your needs, but the idea that our games are so fragile or that players will take advantage by default is silly. To suggest otherwise requires flat out denying the experience of people who have been doing this stuff successfully for decades. Decades.
I'm already the DM with a LOt of House rules, written in perfect legalese. But I don't really want rules for every action, and a lot of the home brew rules are not shared with the players as they don't have pages of legalese protections: players just get the vague overview.Even broadly compatible people aren't always going to get along. Just try getting agreement on pizza toppings and you'll quickly see what I mean.
Further, and perhaps more importantly, being to some degree stubborn is simply in some (or a lot of?) people's nature. And yes, it can go too far sometimes; but standing one's ground is IMO far preferable to letting oneself get pushed around.
Does Earthen Grasp any way ever even slightly effect the Grasping Hand: Never. I'm not going to ever agree, in general, that a weak effect can do anything vs a powerful effect. And I don't agree with giving spells 'wish' functions to falsely make the players creative. The player sits there helpless and is like "oh the only spell I got is earthen grasp...can we say this spell can auto do whatever I want on a whim?" An Agreeable DM will be like "sure cast your reality altering spell to do whatever as you are so creative" They high five and the game goes on.
This is why I often get requests for such house rules: because players want to bend and break them.