They were always meant for emphasis, which takes on variable definitions over time. Terminals were bad at italics due to character box layouts and so the litera

They were always meant for emphasis, which takes on variable definitions over time. Terminals were bad at italics due to character box layouts and so the literary approach of emphasis through italics mutated into emphasis through underlines. Now that we’re all free of monospaced terminal grids, it looks like we’re drifting back to emphasis through italics.