Idk if it counts, but the one cool case for multisig is in escrow. Ie, xmrbazaar 's escrow where a multisig wallet requires input from the buyer, seller, and a mediator to complete an escrow enabled sale. Though I will note that if the sale goes smoothly the mediator doesn't need to constantly be there, just for the beginning parts. But if there's an issue, the mediator can choose to refund or payout.
Notably, I have no idea how multisig would work for a normal wallet or use case. Can def imagine it being troublesome, but I guess friction is the point? But dang I wouldn't wanna juggle multiple physical items for it. Might make sense if it was one hww or normal wallet + a yubikey or something, like 2fa
