I submit that every screw in the world should be the six lobe slotted. For the stuff that’s not tamper-resistant, anyway.
You have the six lobe for actually building things, because fuck Phillips head screws, and the slot for convenience where you could use anything from a coin to a knife.
Here in the US, certain brands of deck screws for outdoor use are six lobe and they come with the driver bit in the box because everybody has the damn Phillips and flat head screwdrivers! But to be fair, if you have a bunch of tools you probably also have a set of torx drivers.