I would imagine most users change their password by only 1 character, and maybe even in sequential order.

When time comes to change the password, it becomes password1234 instead of password123. Or password234. Something easy to remember, most users don't care about best security practices, and changing to a similar password is very convenient. Especially if it's "only" for work stuff

The original idea was that you would take how long it took to brute-force a password, then require the password be changed before that. But we have better hashing now, like bcrypt, where you can tune it so that brute forcing anything would take 100s of years.