Suggestion/Recommendation - Do I need a PSU upgrade?

EDIT: I lied, wattage while gaming (RDR2) is ~750 watts off the wall (not 650 as I said)

Hi all, need some help to figure out if I need to replace my power supply (Corsair RM750i). I recently got an EVGA RTX 3080 FTW Hybrid and figured I would measure power usage. I downloaded OCCT and ran a power supply test, to my surprise Kill-a-Watt reported ~843 watts off the wall!

Looked over RM750i's manual and it says ~89% efficiency at 100% load. So doing the maths, ~843 watts off the wall to deliver 750 watts to the system sounds about right. (correct me if I am wrong, possibly bad at maths)

Gaming wise, I never reached this load. So far when gaming I've only noticed max of ~650 watts off the wall.

Now for the questions part

1. do you think I should upgrade my PSU anyway?
2. if so, which wattage should I go for? (any brand recommendations?)
3. if I don't upgrade the psu and hit 100% load, would I bottleneck my gaming experience? or BSOD would happen before that?

Thanks in advance!

Specs:

CPU: Ryzen 3950x (on AIO)

Memory: 4x4 GSkill Neo Z

GPU: EVGA RTX 3080 FTW Hybrid

Mobo: Asus Crosshair VIII

PSU: RM750i