Energy, resources and time do. Since there are a finite number of resources available along with issues such as climate change, there must still be a way to allocate resources in responsible and fair manner. How this will be managed and enforced globally is anbody's guess.
Honestly I'm not sure you have to worry about inforcement once we hit a certain level. One of the statistics I saw a while ago said that the lowest level of water consumption allowable for a first world level of living was about 6 gallons (22.2 liters) a person per day. That's for drinking and cleaning and laundry, during the week broken into daily equal portions, so actual daily uses will range on either side of that but average out to that.
If you set it at double that per person, and then say no more allowed, people will ask who you think you are telling them how much they can use, and they will look for ways around it. But if instead you develop a water system that collects greywater and processes sewage into usable materials and distills out the water and add atmospheric condensors and heavy rain collectors, Desalination plants ect ect. The people could well consume the same 3 gallons over and over again for multiple purposes everyday, and believe they are consuming from an inexhaustable resource pool.
Water is everywhere, food is made up of mostly carbon, nitrogen, hydrogen and oxygen with other trance elements. What else is made of those elements? pretty much everything. Every time you flush your toilet, throw away a napkin, cut your hair, toss out old ratty clothing, vacuum up dust bunnies, brush your teeth and spit, wash your sheets and clothes, ect ect; you get rid of and forget about large quantities of those elements. What would happen if you didn't take it to the curb, but just crambed that old lounge chair in to a cupboard like it was a garbage disposal and it just made it majicly go away. Then you went about your life making a new couch to replace the chair ect.
So each person could have 2 to 3 times as much matter as they need in their homes and diet in storage at one time and never even feel like they are reusing the same stuff over and over again with only gradual accumulative losses do to the not completely closed and perfect system (exhaled co2, gifts given, population increases, parties, pets, dropped or lost items, entropy...). It's as close to a closed system as we can get and it should do the job quite well.
Over the course of years you may have to replenish the supplies of raw matter, but when this sort of tech is available we'll be looking at colonies on other planets and mining asteroids for materials if we need them. we might even see people using asteroids to build small ships and making them earth homes/world ships headed out into space using bussard ramjets and filtering the stardust and planetary remnants into the recycling systems, building suppplies for cloned or bred or synthsied humans to colonize other worlds or start daughter ships.
The real problem isn't is there enough material for humans on this earth, it's the problem of accessability, and waste of resources. So getting to that point where we can start doing the reuse and recycle points on the reduce reuse and recycle triangle to their maximum potential, will be the hard part and take time, but the upswing is that the only direction is toward that way. It's all just a matter of time frame.