More bans would be alright but...
only if it is done in a way that has some of the bans being reactive (after some champs are picked) instead of proactive (before any champs are picked.)
If you are wanting to add more bans just for the sake of having more bans then you are not really doing anything besides increasing the size of the perma banned pool. Making it preemptive will only increase the number of champs who get in a "perma banned" situation from about 8 to about 14 taking turns getting banned. I want to see people banning Janna and Thresh because they will screw over a team comp that is already being made or banning Cait because the enemy team already has the makings of a good siege comp.