In that case integrated CPU card would be enough. So there is no point to put graphic card there.
Yes, but if nvidia company would care about gaming wouldnt they release just good cards and use reasources to make as close to high end cards? Why waste all the plastic/gold/copper etc to create subpar products just so you can put diffrent number on price tag and that no sane person would use if they had option to pick good GTX?? 950GTX will work on 300W PSU with decent CPU. So argument that those lower cards will conserve energy is also invalid since 950 GTX takes only 75W which is same as most light bulbs. Also you dont waste time and effort to buy PC that will collect dust. If you want play games you dont want crap hardware.
Already answered that. For movies and browsing web you could just use integrated graphics. And all that resources and time that is wasted on making low ends would be put in good use to just produce GTX series.
To prove my argument here is video of 9 years old GTX card that plays GTA V and never drops below 30 fps:
https://www.youtube.com/watch?v=OcnYrSB9xvM