The rests in a song are part of the song. Not every second needs filling.

Silence does work that sound cannot. A rest gives the ear somewhere to land, makes the note after it louder without any change in volume, and creates the sense that someone is in control of the time. Filling every gap comes from nervousness, a worry that attention wanders if nothing happens. In practice the opposite is true, and a held pause makes people lean in.

Take something you have made and remove rather than add. Mute one layer for four bars, cut two lines from the page, leave a shot running a second longer with nothing in it. Then see whether the thing got bigger.