The broad reason for this comes down to the experience.
As I mentioned in a different thread about barriers:
Adding new tools to approach all the levels in different ways creates a lot more new experiences than simply adding new levels to the existing set. Which is good if you’re a single developer whose resources can’t always be spent on just adding new levels to the game forever. It also has a knock on effect when you add in more levels in the long run, too.
As for the booster itself, it adds a new way to approach the micro details in each level. Maybe zones appear in places where it’s nice for ya. Maybe they won’t.
It turns booster firing from something you’d often have easy access to into something you need to take into account during each wave, because not all zones that appear would be ones that you can charge the battery in.
- Manage your battery level wisely and you’ll never run out of boosted firepower.
- Mismanaging your battery charge means you won’t be able to boost when you need to, and that could get you into deep trouble.
It all comes back to my initial opinion about boosters - they offer up different ways to play the game (or more specifically, using different boosters on the same set of waves requires a different playstyle to handle said waves effectively).
This booster has its own playstyle that is focused on planning, movement, and resource management in a neat little package known as the battery. If you like those kinds of things, this one is for you. If you don’t? It’s fine. It still ultimately comes down to your personal preference. Your playstyle is yours to choose, after all.
PS: Also because the boosters market has been just about these two boosters for about 3 years at this point, but that’s just me.