EXACTLY! Part of why I love their implementation of a reaction system is that you get to do things even doing enemy turns, that you can CONTROL and make decisions about! Love it!
Yeah, some here would argue that reactions would interrupt the flow of combat too much... But the alternative is not being able to do anything during the enemy turn at all, which is an even bigger downside and leads to a huge lack of tactical consideration.
The reaction system is really the one major thing that separates DnD and other tabletop systems from a standard turn based game.