Even when driving by hand flathead suck. I worked as an electrical apprentice I have a lot of experience with every screw type. Flathead suck in almost every single application. The one saving grace they have is if the head gets covered in something like dirt or glue or silicone. It’s super easy to clean out the slot and use the screw again. If your Phillips or robby screw gets full of dirt it can take a while or even need a special pick to clean out the hole and get it going again. I’ve heard that on old ships this used to very important because the water would put grime on the screws and build up overtime. With big flathead slots you just use your screwdriver to clean out the gunk and screw away. I am Canadian and so love the robby. But it’s a bitch to clean if it gets full of shit too, not as bad as Phillips though. But the robby doesnt cam out, doesn’t strip. Lasts the longest by far, every other bit will be chewed after a couple months of electrical work in an impact. I can get 6 months to a year out of a high quality robby bit. Ten thousand plus screws. It also holds a screw well to get into hard to reach places.

Idk which screw is the best. But flathead isn’t even in the convo.