Are gift bag the way to go or not?

When it comes to presenting the gift to spend all that time wrapping the gift just to have it ripped apart seems kind of inefficient. If you used gift bags or boxes it seem to make more sense seeing you can use the bag again, so it is more economical over the long run and you don’t have to spend a lot of time wrapping you just toss the gift in, some decorative paper etc, and you are good to go. The downside is the spontaneity of the gift is often not as prolonged as when it is wrapped. Do gift bags work better for adults than for children? Do you favor bags over wrap of visa versa?