You should install Graphene if and only if you have zero need for steam, discord, or anything not in F-Droid AND you actively want to use your phone less. It makes your device drastically less desirable and useful.
If all you ever do on your phone is open a web browser and SMS AND you don't rely on voicemail, Graphene is pretty sweet.
I love the concept, I just found it incredibly impractical. I switched to lineage after six or eight months.
The real thing that made me switch was multiple OS updates per week. The incessant forced updates from Samsung is why I switched phones and installed Graphene. It got so bad that I had to block the persistent update notification and just went without for several months. Lineage is a little more respectful in this regard.