Did you do all the tweaks (Nvidia driver 457.30, settings in NVidia Control Panel, disable Windows game mode, etc…)?
I have G2, RTX 3090, Ryzen 5900x, AMD 570X, and usually have 40-50+ fps in GA planes (except big cities like NY, Paris).
Here are my settings: My 2070 SUPER VR settings and suggestion (Reverb G2 - WMR) - Virtual Reality (VR) / Hardware & Performance - Microsoft Flight Simulator Forums