Increasing complexity makes it harder to brute force hashed and salted passwords from a database. But yes if it is already leaked then you have a problem.
Though I would say that checking against haveIbeenpwnded or another service is a much better mitigation against that.
And 2fa is even better than both.
The truth of the matter is that the owners of most wordpress sites really do not care if it is hacked. Especially if they have a semi decent backup strategy. It is used in so many low stakes deployments that it is kind of silly to force certain levels of security.
Remember it is always about risk/reward. The most secure computer is the least usable one.