Big Bang, an useless skill?

I saw most of the builds max Big Bang at late 18x.

It is still that useless cause of its charged time even though it is buffed in Ascension?

People only use Big Bang whenever he jump down the platform or climb ladder.

So it is not SP-wise to max Big Bang 1st, or it is the last skill to max, since we spend most of the times spamming CL/Para/AR at early 4th job, right?

Actually I/L won't even max their big bang and F/P would probably do the same.

1 SP isn't that bad for 120/121 but its more optional than it was for big bang/chaos.

I think one of the only useful means for big bang was F/P at lhc when they were fire weak.