I don't know if this is what it should be doing, but I remember that on Casual mode, everyone can choose their own difficulty. I frequently choose hard/very hard and lately since the map change has made competitive the default (I like it!) I noticed that I always end up getting "normal" difficulty even though I chose hard/very hard.

Is this a bug or intentional for everyone to share the difficulty on competitive?

Everyone plays on the same difficulty in competitive (as opposed to casual where each player chooses his/her own difficulty).

Hmm, I kind of figured as much. The main issue here is that I prefer the challenge that hard/very hard creates. While I don't mind normal, my only "beef" with normal is that it is more favorable to mono builds.

I still see a great deal of Poison/Trickery builds succeeding which is frustrating to have people do nothing but spam one tower on normal and win.

Indeed mono builds only succeed because of the normal difficulty. For the challenge, there is always -random (but it is challenging to say the least to win in fruit).

There's always the forum challenges and the Forum Draft Series to go for...