Generally, I ask this to graphics programmers (Don't take any harm). What will you do after graphics singularity is reached? People say video game graphics are going to be photorealastic in 10 years.
Movie CGI is already photorealistic. Minecraft is not. You can add an arbitrary (and exponentially growing) computational cost to your game by making the world more dynamic. The games we look at today as paragons of cg advancent are really just static meshes with a few small entities running around. Any step away from pre-baked, pre-compiled and pre-made content will easily consume as many years of tech advancement as you let it. (For evidence, look at how long a modern level editor takes to bake in something as relatively simple as lighting.)
Right now, there is no shortage of things to work on, and things that have not been done yet. I am not currently aware of any horizon past which that won't be true. I don't see any problem yet, and at any rate, there are tons of other kinds of programming to do.