Have you openly spoken to your manager about your concerns? How it doesn’t feel fair? How you feel you’re being treated? There’s a chance they have no idea. Maybe they’re not that experienced and are just working things out themselves. Or if they seem like the wrong person, is there someone above them you can voice your concerns about?
Last time I had an employer I had feelings of being treated unfairly and voiced it and they gave me a big raise and a bonus, and they expressed how they respected me that much more for voicing it. (I did also come to them with a job offer from another company that had a larger dollar amount associated to it.). N=1 here and no guarantees of course, but it’s very worth attempting to communicate.
Being on the other end as a business owner myself now, I realize how easy it is to think everything that happens at the company and how it operates is deliberate and intentional. That is very often not the case. The invisible hand reaches over and forms companies just as it does the economy, eg one person makes a decision and introduced a structure or process 5 years ago and it just hasn’t been revisited despite the fact it should have.
If they don’t seem interested after some good attempts at being transparent and honest, you’re possibly a place that doesn’t value their employees, and it’s worth looking elsewhere to find a place that better aligns with your values.