To me, you aren't mistreated if 1. you're not being physically, mentally, emotionally abused by another party and 2. you aren't being taken advantaged of for your work

Just because 1 member's solo gets a different treatment than another does not means they are mistreated. This is capitalism folks. It's a business decision - it could be that like what was stated above, company underestimated demand and unfortunately, first one up got the short stick; it could be that company thinks Jin will sell better than jhope so put more effort into his (don't come at me, I don't listen or follow BTS, I'm just using these 2 since this is what the post mentioned) or something else.

If this release wasn't up to par for jhope, i do hope he fights for what he wants in the future but it should be because he wants and thinks he deserves more for himself, not because he didn't get the same things as Jin (or anyone else). You don't need to have everything exactly the same for all members in a group, just what works for you and your needs. Stop comparing everything to others and he should just strive for what makes him happy.