Ok I'm pretty sure Samantha could get along just fine in the mortal world without her witchcraft, but if her relatives suddenly lost theirs do you think they could last very long?

Can you immagine Endora, Serena, Maurice having to function without their powers.

Maurice might could get along, he seemed to have real world know-how in many areas.

I dont think none of them would have lasted a day in the mortal world. Especially Endorra.

We SAW Endora without her powers when they were mysteriously transferred to Aunt Clara! And she didn't get along very well.

And we saw Serena and Uncle Arthur without their powers, once. They seemed to use their sense of humors to get by. They might of adapted better than Endora if it was a case of permanent loss of powers.