By your logic, we should dictate all of our hardware / software purchases based on market share. If that were the case...You just proved yourself being a lack of knowledge since you dont even use Nvidia GPU. Do you even aware that Nvidia took more than 70% of market share while AMD is less than 20%?
Operating System Market Share Worldwide | Statcounter Global Stats
This graph shows the market share of operating systems worldwide based on over 5 billion monthly page views.
gs.statcounter.com
We would all be using android phones with Windows computers.Which means we have no need for this website, since clearly no one needs to use macOS, iOS, or any other OS with even less share.
Since this is obviously absurd, you should educate yourself on the comparative advantages of AMD vs NVIDIA. AMD still is the best at dollar-to-performance hardware, though it does not produce the top end gaming GPUs that NVIDIA does. AMD's hardware caters to video editors and photography software more than gaming, as evidenced by the higher AMD core count vs NVIDIA's lower core count and higher frequency. In addition to that, AMD has higher memory bandwidth on their GPUs than NVIDIA, which has specialized application performance benefits as well.
You can compare the NVIDIA GPU lineup against the AMD GPU lineup on any website and they will tell you the raw statistics I just cited. Different markets prefer different hardware with different goals in mind. There is no one size fits all.