In general, the further you get away from origin (0,0,0), due to floating point precision you’ll lose accuracy. Check this post for more info: Floating point precision
So, for infinite runners it’s a good idea to make the character “stand still” and instead let the objects animate towards the character.
Also, for the same reason, you might lose precision in rendering too, so you might need to use midp, or even highp precision in the shaders.