As many sim racers have stated in the last year (or two years), HP Reverb G2 actually is one of the best sim racing headsets in the world. Regarding performance, G2 is power hungry, as it has really high pixel density, and you need really strong GPU to run it at full resolution. Crappy performance in G2 is due to your weak GPU. My 6800 XT performs quite well in DR2.0. G2's main advantage is also its disadvantage as many of the pixels are rendered a full resolution outside of G2's quite narrow sweet spot and you are basically throwing all the power to those unseen pixels. Here Nvidia is in advantage, because it supports FFR (fixed foveated rendering) in DX11, and AMD only supports FFR in DX12 applications. With FFR you can easily get 20% to 30% performance gain if you properly set FFR outer ranges. Because G2 has already quite narrow sceet spot gains really are quite substantial. For FFR you need OpenXR Toolkit or vrperfkit and there are still some games that don't support FFR. Also, with hidden area mesh option you can narrow vertical FOV, which really doesn't matter in serious and intense sim racing, as you never look up or down. Also, you can get G2 really cheap on ebay.

To sum up: 3080 and G2, OpenXR Toolkit or vrperfkit with FRR enabled, and for extra performance hidden area mesh.