Depends how you define it and wether you’re defining it as intentionally en masse or as a byproduct of pure self interest regardless of anything else.

There’s plenty of examples, the most famous one in my opinion is that the popularity of legislation is irrelevant for passage, support by wealthy is. Similarly how the vast majority of people obtain political office is by and large courting the influence of wealthy donors (source - the amount of money being spent in politics and particularly dark money). Also how “lobbying” works even in the Supreme Court and pay to play by definition is politically battling the poor.

99% of zoning is just class-based segregation.

Here's a recent American example: https://www.cbpp.org/research/federal-tax/by-the-numbers-har...

You could do some basic research on this topic, it's been exhaustively covered over the past few centuries, but I'll drop you three starting points.

Pushing the tax burden for upkeeping society off people who own more shit than any of us ever will onto people who have to work for a living.

Legal protection and structural advantages for landlord interests over tenant interests.

Legal protection and structural advantages for employer interests over employee interests vis a vis wage theft, worker safety, worker injuries, etc.

There are many others, but even a brief summary of injustice in any one of these topics is big enough for ~a few hundred books, and alas, the margins of this website are too small to contain them.

where does profit come from? Simply trading items in a competitive market will not turn profits.