If you’re getting input delay and low frame rates regardless of resolution, this will fix your problem.

Fix 1: Enable “low_latency_mode”

• Navigate to “C:\Users\[PC USERNAME]\AppData\Roaming\Bungie\DestinyPC\Prefs“.
• Open and edit “cvars.xml” file.
• Look for the “low_latency_mode“.
• Default value is “0“. Make it “1“.
• Save the file and exit.
• Launch Destiny 2.

This will fix both input lag and low fps problems in Destiny 2.