Everyone gets the same --- we all have a lot in life designed to best get us from who we are and where to are to who and where we're supposed to be. The rich get wealth because their souls need those opportunities, and the challenges that come with opportunity and power. The poor get poverty because their souls need its more obvious challenges. Or, a soul can't handle the challenges of poverty of of being middle class and so is spared from the consequent downfall, whereas another soul wouldn't avoid the corruption or other challenges of money, and it's spared. In any case, each soul is getting the life best tailored for its success as a self-refining "image" of the Divine.
See the Ramchal (Derekh Hashem 2:3:1) that Y e z paraphrases in his answer.
That is why anyone could be rich, regardless of what they own. To quote Ben Zoma (Avos 4:1):
איזה הוא עשיר? השמח בחלקו, שנאמר ״יְגִיעַ ַּכּפֶ יָך ּכ ִ י ת ֹאכֵ ל,
אַ ׁש ְ רֶ יָך וְ טֹוב לָ ְך״.
Who is wealthy? One who is happy with his lot. As it says,
“When you eat the labor of your hands, you are enriched and
it is good for you.” (Tehillim 128:2)
Ben Zoma begs the question: While it is good to be happy with what you have, without care,
it can become a recipe for complacency. If I am content with anything,
what motivates striving?
The the key term to understanding Ben Zoma’s intent is
“chelko—his portion.” What is a person’s cheileq? Well, we are told, “All
of Israel has a cheilek l’Olam Haba, a portion toward the World to Come.” (Mishnah Sanhedrin 11:1)
Our portion is toward — not what we have now, but a goal; in this case a
life’s ultimate goal. A person’s cheileq is not what they have in a moment;
it describes the full path a life takes. In other words, Ben Zoma is not
advising that true wealth is to stop striving for something beyond what
we have, but to find happiness in the journey of trying to accomplish.
So, given a focus on life's goals and working toward them rather than property and the control it gives us, the disparity takes on a whole new light.
There is a story told (Taanis 24b) of R' Chanina ben Dosa, a man so holy that the Talmud tells numerous stories of miracles that occured to him. And yet one so poor that a heavenly Voice commented that the whole world was supported by R' Chanina's merit, but he himself lived off a small measure of carob from one Friday to the next.
Eventually his wife just couldn't handle the abject poverty any longer. He agreed to her request that he pray for wealth. A heavenly hand came down and handed them a huge golden table leg. Certainly worth a fortune.
That night, R' Chanina's wife had a dream. They were in heaven, and all the other couples were sitting at three legged tables. Except for them. Their table only had two legs, it couldn't stand.
Realizing that the third leg of their table was the gift they had received, she asked her husband to pray for it to be taken back. And it was.
R' Chaim Vilozhiner associates the three legs of the table in this story with the mishnah (Avos 1:2) about the three pillars of the world: Torah, Divine service, and acts of charity. The Voice said, after all, that R' Chanina supported the world.
The golden leg they received was the one of kindness. Until now, they had reason not to give more charity -- they had nothing more to give. The story as R' Chaim understands it (I wouldn't say this about R' Chanina ben Dosa on my own), suggests that R' Chanina would have been unable to practice charity as he was worthy to had he had the opportunity.
For them, there was more Ben Zoma style osher in not having property than in having it.
So, R' Chanina ben Dosa and his wife was poor.
And yet, because it was what he and his wife's souls needed, it was also exactly the same as everyone else gets.
