I wonder which of these cards is better. I tend to go to NVIDIA because I currently have an AMD graphics card and have problems with 144Herz presentation, and I really like Shadowplay from Nvidia and the automatic clips. However, I do not really know which of the graphics cards is more powerful. I'm not someone who just plays graphics-consuming games. Currently I play Fortnite and CSGO. However I want that I always have at least 200 fps in Fortnite.
My processor: ryzen 5 2600 overclocked
ram: ballistix sports 2400mhz 8gb
The 5700xt is hardly up to no better than the rtx 2060S. Nevertheless, it is about 40-60 euro cheaper and a little tip: The raytracing on a 2060S is not very good (50-60FPS) but since I have no own experience with because I own a 1070ti but have looked at times on YouTube.
The Radeon 5700 XT is no 10% stronger than the 2060 Super, but it's stronger. If ShadowPlay is a selling point for you (though there's something similar with ReLive on AMD), then take the nVidia. Is in the end jacket like trousers.
Your problem with the unattained 144 FPS, you will get with a more powerful graphics card but also not in the handle. Your RAM limits you properly and if there are only 1x 8GB and not 2x 4GB, the more. Hit the road and buy a 16 GB dual kit with the best DDR4-3200. That should be more effective. The graphics you can namely reduce and compensate for a weak graphics card, against the CPU limit (which is generated by the lame RAM) that helps but nothing.