Nvidia vs AMD is a very large discussion with multiple different viewpoints that can be taken. However, to boil it down to its essence, AMD cards have a higher total compute performance resulting in higher floating point performance which is advantageous in graphics processing of large objects but doesn't necessarily relate to speed so it doesn't increase framerate. However, AMD really stepped up their game, introducing GCN 3.0 on their RX 4xx series GPUs and that's much more optimized for newer games than the Nvidia CUDA technology is. Basically, AMD cards are powerful and well optimized for DX12, OpenGL and Vulkan... Nvidia cards are fast but perform best on DX11 games. It's a tossup of whether you need high framerates or good compute performance.
Compute performance is best used when rendering large objects like 3D models or high resolution videos in applications like Adobe Premiere Pro, while the higher clock speed of Nvidia cards offer higher frame rates for a slightly higher price.