I agree. It's very situational, requires huge investment in prep, an extra five slots (for catnap), familiars all ready to go, probably a surprise round to get all the spells off together, and a bunch of other insane ideal circumstances. A smart enemy wouldn't be caught flat-footed like that either.

The less broken things are just to give your other party members their own familiar, give other party members a single wizard self buff (like Shadow Blade), or combat cast something like Leomunds Tiny Hut. All of which requires downtime or precombat prep.

Wizards are broken in general. This one is just more broken than others.