Wizard gamemode literally relies on one single person, and in most cases, said person will die in few minutes resulting in round not even reaching 20 minute mark, because its rare to get that role and is very easy to screw up/get lynched by crew.
If that gamemode instead would be replaced with raging mages, such rounds would have more action in it, more people can roll for wizard and whole station will be affected by this gamemode, which won't result in <20 minute extended.
It will require tweaking and nerfing/buffing few spells since slaughter/laughter demons are already very devastating, but if it'd be done right, we will have magical version of nuke ops, which is way better than wizard which we have now.