Lower frames than expected in Destiny 2 with GTX 1080

Jan 21, 2019
I recently installed a gtx 1080 in my PC and everything seems to be running just fine, except that when I play Destiny 2, it is well below the benchmarks I've seen online. I'm playing on a 1440p monitor and it drops down to 50 frames when the screen is busy, which isn't terrible but seems a little low to me. Here's my rig:

Intel core i7-3770 3.4Ghz
16gb ram
850w Seasonic PSU
Nvidia GTX 1080

I've tried reinstalling drivers multiple times, found and deleted the CVARS file, changed nvidia power settings to "prefer max performance". Even when I set the in game settings to low, I still get the same number of frames. It could be a CPU bottleneck, but doesn't seem like it would affect the GPU that much. Not sure what else could be causing this. Other games run at the normal benchmark speeds, it's just Destiny 2 that is underperforming. Any help would be much appreciated.