Why did the FBI drop the lawsuit against Apple in the first place? They both made it sound like the stake was much higher than unlocking the one device. Or, th

Why did the FBI drop the lawsuit against Apple in the first place? They both made it sound like the stake was much higher than unlocking the one device. Or, the FBI managed to unlock this phone and so they can unlock any other devices too, now-and-forever? They don't need a backdoor any more? Wouldn't the logical next step from Apple's side be to protect their users in their future devices? Wouldn't then the FBI have to sue them again? Feels like we are missing key facts here, and I wonder why Apple is not talking now.