I mentioned this a couple of days ago in which even if you raise, lower, or just have no bans all together, it's still more than likely going to stagnate to a select few champions per role based off of the competitive tier at the time/patch. There's not much changing to it unless teams are trusting to give other champions or compositions a try, which rare among most teams anyway. And it's not even as simple as "balance faster" because it'll still shift to a same stagnation eventually; not to mention that it's a game first and a competitive scene after.
To remedy the diversity point though, week 1 across premier regions alone had a diversity of somewhere around 80 Champions played at some point. So that's definitely something to point out as even an indication of each region having their own different flavors to bring out.