Have physicists considered the possibility that quantum physics differ from macro level physics because macro level physics has organization. Quantum level particles behave as independent individuals able to each do their own things like individual humans.
Larger "particles" are collections that behave as a group instead of as individuals just like the way humans may behave differently as individuals and as groups.
Gravity may be a function of organization meaning that there isn't a quantum level equivalent to gravity. Gravity doesn't just confine matter to a general location. It allows matter within its confines to be distributed according to density of areas of matter. For example, a human holding a tank of helium and a large uninflated balloon cannot rise above the ground. However if sufficient helium is released into the balloon, even though the total mass won't change, its distribution over a larger area allows it to rise above the land.