Why did Thanos, with the power of all the infinity stones, never think to try doubling the amount of resources in the world?

If you have the power of reality, spacetime, the mind, etc., surely you could snap in more fresh water, food, metals, plants, etc.? Was he just stubborn and didn’t want to let go the idea he proposed on his home planet?

Also, how does Thanos survive “snapping” but regular people using the power don’t? Does that imply that the type of people on Thanos’ planet is “superior” to everyone else (in my opinion, nobody should survive it because the stones are essentially the power to control every aspect of the universe itself)?

One thing of note, Thanos in Infinity War shows that you could use the stones individually (and also other characters, like Vision using it as his brain/the power source for his thinking bits and Dr Strange using the time stone to manipulate time) and that doesn’t kill Thanos or any other character it seems. Why is that, are the stones meant to be more powerful together? Also, what happened to all the stones, were they all returned to their hiding place (and if so, why weren’t they used for doing good stuff, like space stone could be used for fast travel, soul stone could bring back the dead, mind stone could solve the mysteries of the universe, reality stone could make awesome virtual reality games…)

And finally, and definitely very important, why is Thanos purple? Seriously though, why? Is it because of the comic books (like Hulk being green), or is there another reason? Did he just need to stand out from everyone else?