It's nice to have a higher frame rate, but sometimes you want to peg the game back just a little. Annoyingly, Destiny 2 only lets you cap your FPS to 30 or 60. But there's a way around that.
For anyone who's recording or streaming their gameplay especially, you don't necessarily want your frame rate to go all Icarus. But Destiny 2 right now doesn't have in-built caps beyond 30 or 60 FPS. So, people came up with their own solution.
If you'd like to cap your FPS to something more reasonable - like 120 or 144, for those with high refresh rate monitors - here's what you do:
Navigate to your C:\Users\PC NAME HERE\AppData\Roaming\Bungie\DestinyPC\Prefs folder.
"PC NAME HERE" will be the name of your system as far as Windows is concerned. If you don't know what it is, you can find out by typing "System" in your Start menu and reading the computer description name on the screen that pops up.
Edit cvars.xml, using Notepad or something similar (like Notepad++).
From there, you'll see a whole bunch of lines like this:
You'll want to navigate down to cvar name="framerate_cap". It'll be one of three things: 0, 30 or 60.
Edit this to the value you want - I chose 144 - and then save the file. After that, right-click on the file in the folder, go to properties, and set the cvars.xml to be read-only.
From there, you can enable the in-game FPS counter to check that the frame rate is hitting your desired limit. That's the only FPS counter you can use for now, since Destiny 2 explicitly blocks screen overlays from third-party applications, like the ones in MSI Afterburner, EVGA Precision and so on.