God's justice does not mean that he distributes sustenance equally among his servants; Because equality is completely different from justice.
differences between justice and equality
differences
Ayatollah Mojtahedi Tehrani (RA) used to say,
When the doctor comes to the patients, he prescribes food according to the condition of each one.
Soup for one and kebab for another! Can a person for whom the doctor prescribed a new soup say; why did you prescribe kebab for my roommate and soup for me!
the doctor has written for his/her own good.
God's justice does not mean that he distributes sustenance equally among his servants; Because equality is completely different from justice.
Equality means putting the same amount of food on a three-year-old child's plate as you put on a forty-year-old man's plate, but justice means calculating everything correctly, considering everyone's benefit, and not trampling on anyone's rights.
Our Lord is just in providing sustenance. That's why he said:
Allah makes the sustenance wide for whomever He wills, and narrows it for whomever He wishes [and deems expedient][1]
Reference:
[1] - Surah Ankabut.62. اللَّهُ يَبْسُطُ الرِّزْقَ لِمَنْ يَشَاءُ مِنْ عِبَادِهِ وَيَقْدِرُ لَهُ ۚ إِنَّ اللَّهَ بِكُلِّ شَيْءٍ عَلِيمٌ