Q1:
Tomshardware - They have charts for few generations of GPU on both AMD and Nvidia.
https://www.tomshardware.com/reviews/gpu-hierarchy,4388.html
TechPowerUp - Every TechPowerUp GPU review have relative performance graph that include 2 generations of GPU, not all but a lot.
https://www.techpowerup.com/review/?category=Graphics+Cards&manufacturer=&pp=25&order=date
Q2:
For VR I usually just refer Youtube. Babeltechreview is the only website that I notice consistently do VR benchmark.
https://babeltechreviews.com/vr-value-wars-the-hellhound-6650-xt-rx-6700-xt-vs-the-rtx-3060-3060-ti/
https://babeltechreviews.com/first-look-at-arc-vr-performance/
https://babeltechreviews.com/hellhound-rx-7900-xtx-vs-rtx-4080-50-games-vr/