Well. There would have been no one to watch over or train luke. The sandpeople would have killed him probably.
Then the empire would have won and the Jedi die out, forever. Or at least a long long time. The rebellion would have been screwed with no one to take out the death star.
There's an opinion I have, you probably don't want to hear. But I'm telling you it anyway.
Obi should have mercy killed Anakin, rather than leave him to burn slowly to death. That was a dick move, mostly.