With the GPU shortage finally behind us, we're at a point where the price of entry-level Nvidia cards has dipped enough to make them a real consideration for mainstream gamers. And while Nvidia's RTX 3070 is still on sale at a premium, AMD's RX 6750xt offers a compelling alternative that should be able to handle all of your gaming needs.
Both the RTX 3070 and 6750xt are excellent cards for 1080p gaming and will be able to comfortably push any game at max settings with high refresh rates. That being said, the RTX 3070 does have an edge over the 6750xt when it comes to ray tracing performance.
This isn't a one-to-one comparison though as their respective architectures are very different. Each card has a certain set of cores with shaders focusing on lighting and shadows, RT cores working on ray tracing and TMUs creating 3D objects from bitmaps. Despite this, the two cards perform very similarly in most tests as both have been optimized to work best on their respective architectures.
However, when you start looking at rasterization performance at higher resolutions like 1440p and 4K, the 6750xt starts to have an advantage. This is due to the fact that the AMD card has more VRAM which it can use to boost framerates through features like Smart Access Memory and Radeon Super Resolution. This is a big advantage over Nvidia's DLSS which requires developers to implement it into games for it to be effective.