I think 2 can also be used as an argument for why they should switch it up. After all, we switch playable characters each game to keep things fresh, so why not do the same with guns? A new planet should bring some new gun modifiers, and they could still bring back some of the old manufacturers as rare loot or legendaries to get even more variety. After 13 years and 4 entries, I’m just a little tired of reloading Tediore’s and throwing away all Hyperion and Torgue guns I pick up (exaggerating!).

I somewhat agree with you on movement: it doesn’t have to be for combat or necessary. But you have to adjust the enemies to account for the extra player tools lest you make melee or slow projectiles trivial. That and I believe that the best games implement features that solve something, even if the devs create the problem the feature solves. Take Doom Eternal for example: I wouldn’t have used half the tools in that game if they hadn’t provided challenges that were best overcome by using them. On medium-high difficulties you end up using everything at hand to get through the levels because otherwise you die, and that’s fulfilling! If I had the same tools at hand but the enemies were all .5x speed then it wouldn’t be very engaging.