How common is second-hand subbing?

I would like to chime in and point out that when subbing or editing I can hear sometimes the Korean speaker say like 2 or 3 words but in English it’s a whole long sentence… I truly wonder how does this translates in so many more words or expressions? At times it’s strange to me, that in English there is been said so much while in the original language it’s not, I even wonder how much is actually added to it, if that is really that what in the script is?

I find the opposite is more strange: trying to convert your own language to mirror the structures in the original.

Oh!!! That’s because a “what” never means a “what.”
Oftentimes Why and what are the most simplest, but have more meaning than that.

What do you want ==> what
How is that so==> why
come again==> what
how could that be==> why

See how things could get lost? A lot of what I’ve found is the balance btwn go literal vs. be contextual. A good translation finds a way to recreate in the new language.