People sometimes aren’t sure whether they manage it in time to destroy the castle gate. Also, lasting spells like sonic blast their effect can be transferred to more buildings by run forward technique after using a time warp scroll.
Armageddon will solve a difficult situation for you. For example when you are under very heavy attack by skull towers, gargoyle towers (you name it) and can’t manage the situation with the arsenal currently available. For example spells are in cooldown and if you don’t use the scroll, it would mean end of your army and probably end of raid. Or a situation that even your spells won’t help you to deal with the extreme situation you are currently in. Then an armageddon scroll could be the answer. Also in top teams where a lot of players tend to put firebolts or lightning towers near the gate an armageddon scroll could be the solution to destroy towers on both sides of the gate. time warp won’t help you there, as soon as the gate is destroyed the raid is over. Top teams demand 100% raids.
When you can handle the situation and only need a little bit more time (for example you spend to much time) or you can handle the situation when things would be in slow motion then a time warp can be handy. I used them couple of times in dungeon levels, just to make sure I would not run out of time. It’s just an extra security.
Last but not least, time warp costs less gems than an armageddon scroll.
An improvement of the game would be that knocking down the gate while not 100% is gained that the raider still gets that remaining time to take down the remaining towers until either remaining time is over or 100% is scored. If that would be implemented, we would magically see no towers near the gate any longer, but I bet it won’t happen, since Flare also benefits from the required scrolling to get 100% scores.