I found out the hard way its not just about battle power but levels as-well.
Coming into a game with gear from PSO2 I got to Battle Power 1184 by 12th level only to find out my level was too low and my damage would be reduced because of the enemies in the UQ were lvl 17.
For me its like this:
Imagine playing dungeons and dragons and being 5 levels lower than the boss monster.
The DM penalizes you by reducing your damage.
You kill the boss taking longer than the norm.
The DM then decides to give you barely any exp for the time, effort and skill to kill said boss( Sounds like a vindictive DM now doesn't it).
It has happened to our group in DnD in the past and the whole group let that DM know it ruined their campaign and thus the whole experience.
It is the first game Ive played that reduces your damage for being 5 levels below monsters and gives bare minimum exp when you actually kill the monsters anyway. I did this solo so I wasn't leeching or trying benefit off others hard work as I can understand the point about leeches just hanging nearby not doing much or helping out.
While I don't hate this new system, I dont really like it either at this point.