realistic Terrain

please make the Terrain a bit more realistic as for some odd reason i have been getting plains biomes that are rather hilly and same goes for savanna biomes which are actually quite flat most of the time, there is also the fact mountains are generated in a weird way where it is more like pillars stitched together then actual mountains, rivers also suck cause they don't generate realistically cause lakes and rivers could be found above water level like with water falls, up hill lakes, and downhill rivers, also the general terrain generation is weird as it is extremely bumpy and isn't smooth as if erosion and plates created the Terrain, please at some point go back to the Terrain generation and rework it.