You will potentially find use for multisig in any scenario where multiple people are involved:
  • Treasury management where you want to limit discretionary spending (company, family members) - remember that keys do not have to be equal, some can be privileged (CEO, parent).
  • Escrow services which are typically 2-of-3 where the arbiter/lawyer holds one key in case parties cannot come to an agreement between themselves.
  • Timeout 1-of-2 inheritance where the primary key is used normally but if a timelock expires within, say, a year, the secondary key can also access funds (therefore as long as the primary keeps moving them and refreshing the timer, it's a "proof-of-being-alive" aka "deadman's switch").
  • But even for a single person, it offers a plausible deniability against violence, as well as a gateway to geographically-distributed backups.