How important were press gangs to naval recruiting?

Were press gangs the main way sailing navies filled their crews?

No; impressment mattered in some circumstances, but reputable officers often recruited volunteers through their own fame and success.

The popular image exaggerates press gangs as the normal foundation of a ship's company. Impressment often produced landsmen rather than the skilled sailors a warship most needed. Successful officers cultivated public reputations for competence, prize prospects, and survival, then used that fame to attract volunteers. Press gangs became most necessary when a commander was unknown, distrusted, or recruiting during an unusually desperate mobilization.