What proof is there against evolution? Why do people still believe in creationism?

This should help you

It goes beyond "fake" and "real". Reality itself is not real by the standard that either side puts forward. There are forces greater than human on both sides, doing their best to win the war over control of reality. You have the Creator and the Designer playfully competing, but though playful it is also for a greater cause, both having outright armies on their side to fill the holes in their justification through time and space (as the dimensions beyond this one do not have the same type of time, and moving in the fourth dimension allows altering the past and future in ways that affect the present, and the higher the dimension, the greater those effects are) so there will be a perfect world one day. Creation is not complete, its design is flawed, but someday all the blanks will be filled and all the pieces of the puzzle will fall in place and no corporeal lifeform will ever know that there was ever anything wrong.

Evolution and creation are not mutually exclusive. Neither is true yet, but neither is false either. Whichever wins in the end, the greater good is all that matters. Humanity is just one tiny part of the competition, albeit an important part at that… but it is and has always been expendable. Reality is not stable and as such changes can easily be implemented, much like the code of a game or the script of a movie.