I am on the fence about these in the game. On one hand they are neat little thing to level up and boost that number next to our gamertag. But on the other, it also circumvents the power grind by allowing you to brute force it with bounties and milestones. In doing so, certain activities like raids and nightfalls get easier as the season goes on. And its not because we as the player get better and more efficient at them. It's because it is literally easier. Adds deal less damage to us and we do more to them. Then for certain things like Grandmasters, to keep them difficult Bungie has to cap our level at a certain point which then makes getting the extra levels feel pointless. Or like Master Raids, Bungie has to set the power level borderline unreasonably high to account for Power Bonus Levels. I just think that limiting the number you can get, the rate at which you can get them, or even outright removing them might be better to keep the peak endgame content somewhat challenging. Obviously, if Bungie does do that then certain levels of activities would need to be rained in, like Legend and Master Nightfalls/Lost Sectors, so that are challenging but not obscenely difficult-by-level all of a sudden.