(Nothing lasts forever, sure thing, or for ages, and it's a question how much can or should anything last or occupy attention. A single line can register as a poem, monostich, the line "break" take effect from the practice of poetry.)
There doesn't have to be anything like padding anywhere at all, when there's no metre or regular rhyme, and a piece of language in verse, measured, deliberated, can really be a stretch, process of thinking, one thought really attained, in a second or longer time, leading to another, a math of everyday life, penetrating or anyway evaluative, the line (/)- or stanza (//)-break providing a means of assessment, the stress it can give in the absence of obscuring metre, a regular beat. The line is a typographical device as much as a comma or colon, after all, as is indentation, lacuna too. A thing can be overemphasized, made too much of, yet it seems that, ultimately, one is as important as any other, there's no hierarchy, so evaluation or assessment amounts to realization.
Larry Eigner, "not/forever/serious," quoted in Robert Grenier, "Realizing Things"
Also, the space in which the line appears. And, maybe, reading backwards and forwards (i.e., leaving aside payoff), the space and spaces within the line. The movements and reverberations. The role of the "break" in creating this space.