Every time we have 9 maps for team pool , 3 is static (arena , bf , arabia) , 3 is chosen by devs, 3 is decided by votes.
What happens in this case is, we wont see new maps. For example , we will get hideout next pool, and next next pool we will probably get lombordia or smth which we already played 5-6 weeks ago, so basicly hideout, oasis, gold rush, lombordia etc keep rotating and we wont see any different maps.
I know sometimes we get new maps such as crater etc, but they only are chosen once, so we wont get it anymore like amazon tunnel. I think amazon tunnel is chosen after it released and then it didnt come again.
Therefore, what i think is why we wont get more options like 18 maps or smth with more ban,and make some maps static such as hideout judging from votes it is one of the map which got highest vote so far.
tbh, i think we should have unlimited ban but it isnt main point of this discussion.