The CR's glass ceiling

One of the sillier parts of the D&D rules is that monsters are arbitrarily limited to specific challenge ratings. For example, almost all demons except imps are at least double digit CR, almost all humanoids are single digit CR, etc. I am tossing that out the window. In my cosmology, every family of monsters has representatives at every CR bracket. There are low level demons and mid level demons, mid level and high level goblins, etc. Sure it is a pain to make those statistics myself, but I refuse to be forced to throw in random monsters just to maintain CR parity. Since 5e has that whole bounded accuracy thing borrowed from AD&D, I only need a few entries for low level (1-4), mid level (5-9) and high level (10+). The vast majority of campaigns never reach high level anyway, so high level monsters are kind of pointless.