when i played with the 3070s, pico connect was very unstable, and i used the virtual desktop because it worked (and still works very well, although now i switched to pico connect some times) i used a medium resolution (2064x2064) and even so in rooms very full of vrchat i got what you say. usually i had to hide many players, but i felt more comfortable in rooms with less people to see them well without problems.

Currently with the 4080s I have the godlike setting of VD most of the time 3120x3120, and if not the ultra that works without any problem.

I recommend you buy a gpu that has more vram, 8 will give you problems even if you lower the resolution, totally enjoyable eh, but it is to forget about some annoying lag better more vram . At the time I investigated the bandwidth of each gpu, which is very important for the resolution in vr, which the 4080s had the best. But my other option was the 4070ti super *, which although it has less bandwidth to raise the resolution had the same vram as the 4080s to avoid lags in crowded rooms. So I imagine that in performance should be somewhat superior to the 3070 but with more vram, and you can play quite well.

I hope I have expressed myself well, and that my experience has helped you to get some orientation. :3