In the world we are today, everyone needs money, that is why most people work earnestly just to make money, not that they are addicted to it but they are just trying to survive because it's not easy, someone can't really survive in this world without spending, either buying or selling but in one way or the other, one must spend, especially for married couples, it's not really easy for them to stay or take care of their family without money, so they need to make more money even if they have where they are working to earn for a living but still they will need a side work to support their hustle, to make sure they meet their ends meet.
More money means more life security anyway, without money we can't afford good insurance, without money we can't really survive as you stated depending on the welfare program isn't really a solution either, we as a citizen expected to make contribution through taxes.
so its rather understandable that someone will try hard to secure their life, trying to prevent whatever bad thing might be happening to them through earning more and more money, the entire system world wide depends on the monetary system meaning the more money we got then we are probably on the winning sides.
can't really blame people to really favour money when its the thing that truly needed to live in current economic system.
Op that scale of analysis is correct but you have to know that everyone in the world is want to make more money and the only people who are not interested to make money are the wealthy people and who is the wealthiest man in the world is unknown. But we have world richest person and the world richest person too is still looking for more money so nobody is exempted. Rich people work to maintain their rich. So money is something that makes people to be addicted because we must survive.
its not that wealthy people don't really seek money but its just that they are seeking money on a grander scale, the small left over money doesn't matter to them that much anymore because probably their dream is already different than most of ordinary people.
you know its probably because when they are rich they quite literally can buy anything they don't consider luxurious stuff as something they sought after anymore.
at that point as you said they just probably just trying to maintain their wealth and that's it.
but frankly, there are still many billionaires out there that keeping seeking more and more money and probably trying to set a record.
overall, their purpose is already differ compared to normal people probably they just want to be over achiever even though they already are.