A phrase almost certainly has a lot more entropy than the layman's reused password from other leaks.

If this is a phrase to unlock a bitcoin account with 1000 bitcoins in it, then you can easily convince people to try and brute force it.

Do you have Amouranth's or xQcOW's salted hash from this leak? Might be worth trying to brute force it.

You try on those kinds of accounts because they might have re-used it or the password might be patterned or not completely random, which gives you a chance that the credential might give you access elsewhere.