There are no real numbers on this, but…
A lot of people lost their bitcoin by:
  • losing a HWW
  • losing a passphrase to a HWW, thinking it was similar to a website password
  • trying to make single-sig too complicate because they recognize it‘s a fragile setup
Collaborative custody multisig w/ unchained / referencing their step by step resources avoids ALL of that. W/ multisig, there’s no need to make anything complicated, and no single points of failure means no human error is going to result in loss in loss of funds all of a sudden. If you make a mistake, it’s really easy to fix it and move your bitcoin to a new wallet.
Secure single-sig is WAY more complicated and fragile than multisig