Pure pixel pushing performance, AMD is better than NV for a given price. NV has worked really hard to give you other reasons to go for them, though. Like the latest Radeon Catalyst drivers are a shitshow (again), DLSS works much better than FSR, and if you're the sort that gets things at release NV are way better at having the driver ready for it. On the higher end cards, they're a fair bit more powerful at raytracing, too. (But I don't think it matters so much at the 6700/3070 level)
Edit to add: RX6700XT was between a 3060Ti and a 3070. Now the 4060Ti is pretty much dead even against its predecessor, but the 4070 is a fair bit faster than the 3070. The 6700XT is nowhere near 4070 level performance.