The Shazam powers come from the Greek Gods ( back in the Golden and Silver Ages Mary's powers came from Goddesses I forget if they were all Greek).
Ok, Solomon wasn't Greek but 5 out 6: isn't bad.
While the connection to Greek mythology for these characters isn't as strong as it is for Wonder Woman, it is there.
Besides if they already used Silvana and Black Adam is getting is own movie, that is pretty much it for the Shazam rogues gallery.
Classic Marvel family spent most of thier time fighting Sivana and his family of evil geniuses. If you aren't using them...
Good luck trying to get Mr. Mind to work in live action. Ibac is a crappy version of Black Adam and Captain Nazi...
No point even going there...