Kenobi - S1E3 (Spoilers)

I don’t think that would satisfy many people and justify them making a kenobi show. Why would they make a Kenobi show with only minor villains?

Because it's named "Kenobi" and not "Vader"?

And because in his current state of being cut off from the Force, 3rd Sister could kick him from here to January with one lightsaber tied behind her back?

The real villain here is Kenobi himself: he's cut himself off from the force and needs to regain his relationship to it. With it, he can defeat Vader (as we've already seen). Without it, you don't need Vader b/c lots of enemies are more than a match for the run-down, near-powerless has-been that he is in his current state.