The point is, the context is not present in the card. So why should it be present in the translation?
I get that in some (most?) contexts, you actually need a natural translation. This can often depart from what’s actually in the other language quite a bit. Watching anime for example, you see dozens of instances where a simple はい is translated as “Yes Sir” or “okay” or “got it” or “understood” or “here!” or any number of other things, because in English we would naturally use all these different phrases depending on the context.
That’s fine and a mark of a good translator, because the point in this case isn’t to teach Japanese; it’s to give English readers/viewers a chance to enjoy the story as it would be if it had been written in English.
But for us Japanese learners, it’s actually really interesting and useful to notice that in all these situations, the word はい is used. I’m going to think of this as “Yes,” and embrace the way Japanese can make this one word mean so many different things. And then when I’m speaking with somebody and in a context where in English I would say “got it,” I hopefully won’t trip over trying to translate that (持っています?!?) and will instead remember to just say “Yes,” because that’s how I’ve been thinking of it in such situations all along.
The omitted bits are the same thing. If I’m translating a manga or anime or otherwise producing content that (1) has actual context, and (2) is meant for consumption by ordinary English speakers, then of course I would do my best to write natural English, regardless of how closely it matches the original Japanese.
But if it’s for my own purposes, what’s the point? I don’t need to become a better English writer; I need to become a better Japanese reader. If I can (1) eliminate steps, so that it’s faster, and (2) more quickly learn Japanese speech patterns by using English that’s as close to it as possible, then why the heck not?