Firstly, the Islamic System does not mean every individual that is a Muslim in society is just, but rather the system of governance and laws need to be that of an Islamic nature.
A good trip is one where the vehicle of transport is in good order and the driver is experienced and the destination is reached, not that none of the travellers will not experience any glitches.
No one surveys every single passenger on every trip, but rather the concern is more about the skill of the driver and the safety of the vehicle used to transport.
In Ayah 102 of Surah Baqarah, we read a group of people choose to follow Satan rather than Prophet SAWA Suleiman AS (A Divinely Guided Prophet SAWA whose kingdom was divinely gifted).
وَٱتَّبَعُوا۟ مَا تَتْلُوا۟ ٱلشَّيَـٰطِينُ عَلَىٰ مُلْكِ سُلَيْمَـٰنَ
“And they follow what the Satan’s recited over Solomon's kingdom”.
Secondly, Justice does not mean equality in all places. A just doctor does not give the same medicines to all the patients, a just teacher does not give the same marks to all the students, rather, this is equality and completely unjust. Are the cells of the eyes the same as that of the bones in the foot? Are the cells of leaves, fruits, mountains, fields, minerals, jungles, planets and galaxies, colors etc. all the same? Differentiation is of two kinds: One is with wisdom and with the truth and the other is discriminatory and against the truth.
Sometimes inconsistencies are based upon oppression which must be fully opposed. Traders that are aggressive, short sell, hoard, conspire, embezzle, steal, run shark loans and similar activities must have what these extracted from them. However sometimes inconsistencies are due to the effects of work, skill levels, expertise, administration, initiatives and similar issues in which divine rights (such as Khums and Zakat, religious charity) can be paid to. If we don’t want to pay for the rights of initiatives, skills, work and expertise, society will stand still and growth will not occur.