Specialization, blindly following authority, widely applying idea of ownership and lack of self-discipline are some of the key secondary reasons why our society is bloated.
The primary reason which allows these secondary reasons is fear. Fear messes up our list of priorities in life and makes us not look farther than our collective noses.
What is the bloat of society and how is it generated?
Due to the reasons described above, the world is fragmented. Most individuals carve a piece of the world just for themselves, not sharing with anyone.
To keep such a fragmented world up and running, an enormous overhead of time and energy is required to keep the pieces from falling apart immediately.
Narrow social protocols (such as laws and formal politeness) heavily restrict human interaction so as to keep the fragments from clashing with each other and disturb the workflow of the gears of society.
The capitalistic system puts the cost and reward of bloatedness mostly into the hands of the individual, where it's up to one's choice and self-discipline to decide what to do with. Most people just try to make their own fragments appear shinier than the others'.
The communistic system deals in collective cost and tries to come up with a collective reward, but it's usually someone's already bloated ego which projects itself onto the collective. The worthless bliss of ignorance is all that's left as a reward.
The globalization process makes things more efficient.
If the local villages converted the overhead of time and energy into strength, the global village would be the epitome of fiery will and responsibility.
If the local villages wasted the overhead of time and energy on bloat, the global village would be required to waste even more time and energy on bloat.
There is a limit how much and how fast can bloat be produced before it brings down the system that produces it. We, the human society living in the global village, are approaching that limit.
Ultimately, it is the human individual who creates and desires the bloat. With practice of self-discipline and fearlessness, the cycle of self-destruction could be converted into a cycle of self-empowerment.
A good place to start would be overcoming fear of death in all its aspects, including its most shiny little sister - complete emotional attachment to ownership of objects.