If this may help, there is a temporary solution that may help you. I've tried this myself with my 2060, but I cannot confirm if it'll help you or not, but it wouldn't hurt to try. If you go into your NVIDIA Control Panel, go to where you can select 3D settings for specific games/programs, have it selected to Destiny 2, and then turn Shader Cache off for just Destiny 2. This is a temporary workaround, but it worked for me and I'm getting the performance I used to get before BL, and I think it was that something happened in the game code that caused Shader Cache to only hinder performance for that game instead of improve it.