Draft needs an 'optional bans' system as the roster gets even larger.
Instead of a fourth or even fifth ban per team, draft needs something like optional bans:
After the regular three bans per team, there is then an optional ban phase. The team who was second to ban gets an optional pick after their third ban. They can either ban a fourth champion, or defer.
If they take another ban, the other team can now take a ban as well, or veto the ban and the ban phase is over with just the original six bans.
If the first team deferred, the second team then has the option to ban a fourth champion, or also defer and end the ban phase.
This can happen for a fifth or even sixth pair of bans, for up to three more bans per team, unless both defer or one vetoes a ban.
Turn the bans into a bit of a poker game really. Bans can then adapt to break stale comps or leave the options open.