I was just speculating in this case but my understanding of this industry is that if the product earns money then everyone gets promotions and bonuses. It's not about individual ability.

My point is that there is no correlation between the financial success of the product and the skill of the UX designer or developer; yet financial success is the main metric which is used to determine rank and pay for these specific roles.

I'm happy for sales-people that their pay fully correlates with their performance but as a software developer, it really sucks. My pay correlates much more with the performance of my colleagues in sales than with my own performance. If I'm unlucky, the correlation may in fact be inverted.

I've seen this over and over. I worked in blockchain space; the developers before me wrote TERRIBLE code, the thing was literal spaghetti code, full of vulnerabilities and it's a miracle it didn't get hacked. But the timing was right and many of those early developers earned big money as crypto prices soared in the early days... The people who joined only a few months later and pulled off a heroic redesign/refactoring effort and did an amazing job in record time got peanuts because the hype was dying down. So the fact that they improved the product 100x didn't matter at all. It's like there was 0 recognition.

Bad luck compounds. I could write an entire book about this effect... But that book probably wouldn't sell; ironically, a victim of the same effect it would be describing. People only care about success stories. With good luck; not only do you get to be successful but you get to sell books about it which makes you even more successful. Good luck compounds too.