Do commercial airliners use supercritical airfoils?
Supercritical aerofoils are definitely widespread in modern airliners, including the A330. In fact, the A300 which is the predecessor to the A330 was one of the first airliners to fly with a supercritical wing.

The reason for this is that maintaining slightly supersonic flow over the majority of the upper surface keeps it at high speed, hence producing low pressure and lift for longer and it also shrinks the shock from flow decelerating back to subsonic, compared to a conventional foil. As well as these direct aerodynamic benefits their thicker t/c ratio compared to efficient conventional sections makes the wing structure easier to design, making them a no-brainer for pretty much all modern airliners.