Thrown weapons are usually used when characters can't make it into melee range on their turn and still want to attack. The assumption is that they will close next round.
If the entire entire encounter happens at greater than a 30' range every attack will be at disadvantage and they will only have enough weapons to engage for a few rounds at most. Plus, depending on the environment you may not get those thrown weapons back.
If the entire entire encounter happens at greater than a 30' range every attack will be at disadvantage and they will only have enough weapons to engage for a few rounds at most. Plus, depending on the environment you may not get those thrown weapons back.